How tall is too tall? Height, weight, obesity, longevity, growth, ecology, environment, survival

                                         

                             How Tall is Too Tall? A Review 

  Examination of the health, obesity, longevity and environmental
  ramifications related to increasing height and weight.

  Thomas T. Samaras, Researcher, Reventropy Associates          

Key words: height, obesity, chronic disease, longevity, telomeres, growth, nutrition, birthweight, intelligence, ecology

Abstract

Height and rapid growth are explored in terms of their substantial impact on health, performance, obesity, longevity, the environment and resource consumption. Also described, are the undesirable consequences which result from increasing birthweight, fast growth and early sexual maturation. Findings are also presented on the obesity epidemic and its relation to birthweight, accelerated growth and greater height. Numerous studies are reviewed showing the relation of height to cancer, coronary heart disease, all-cause mortality and longevity. In addition, the heights of centenarians and supercentenarians are examined. Robust data from animal studies showing a relation between size and longevity are also presented. Several biological mechanisms are provided to explain why larger body size is negatively correlated with longevity. In addition, intelligence and its relation to height is evaluated. The paper concludes with a summary of the impact of increasing body size on resources, the environment, economy, and national security.

Introduction

Greater height has been widely viewed as an indicator of social status and privilege.1 This is a highly ingrained belief that we all learned in childhood. On the surface, this viewpoint makes sense because we are told that taller people earn more money, are smarter and stronger, and make better leaders. Since taller people tend to be the products of favorable or enriched environments during their youth, there is considerable truth to this perception. Unfortunately, in our height-biased society, these beliefs become self-fulfilling prophecies and create the false image that average or shorter height people are somehow less talented and healthy. However, Sandberg,2 Samaras,2  and Rosenbloom3 have reported that short height is not a physical or performance handicap based on historical data, clinical research and empirical findings.

The “taller is better” thesis is so ingrained in our world that virtually no scientists have systematically examined how increased body height and associated weight relate to our physiology, physical performance, health, longevity, intelligence, economy and environment. However, there is a growing number of researchers who question the belief that maximizing growth and greater height is always better.4-11  For example, Marini et al 8 have stated that lower energy intake, slower growth in childhood, and reduced height doesn’t necessarily indicate impaired development and may have health advantages in adult life.  Alexander10 also noted that shorter and smaller future humans would increase humanity’s chances of survival. And Cannon7 observed: “Bigger and bigger is not better and better. To the contrary: the principle that accelerated growth means health, and that for this reason animal protein is the master nutrient, has proved disastrous.”  In addition, Rolland-Cachera11 conducted a review of the literature and found that rapid growth in weight and height early in life is related to cancer, cardiovascular disease, diabetes and obesity later in life. Other researchers, such as de Magalhaes and Faragher,12 have found that smaller individuals within the same species tend to live longer. They report that this greater longevity is achieved by avoiding the higher rate of cell division which is a natural part of producing and maintaining a bigger body.

The common belief that increasing height is healthier was contradicted by Holzenberger et. al.13 who showed that shorter men live longer. They tracked 1.3 million men over a 70-year (y) period and observed that failure to associate growth in height with reduced longevity during the 20th century is due to the masking effect of improved lifestyle and medical progress.  In addition, an in-depth study by the World Cancer Research Fund and American Institute for Cancer Research (WCRF/AICR)14 reported that the move to urban living and industrialization has not only increased our height and weight, but has also increased obesity and chronic disease, such as coronary heart disease, diabetes, and some cancers. 

The following provides a review of findings on body height that are counter-intuitive and difficult to accept. While there are social and physical benefits to being tall, the negative ramifications in terms of health, fiscal costs and human survival need to be critically examined. A brief background discussion is also included.

Background

When my  research began 35 y ago, I was not aware that increasing human body height  was in any way harmful. Instead, the Second Law of Thermodynamics stimulated my thought on how this law applied to the human system. Briefly, the Second Law states that all systems in the universe proceed from an ordered state into a disordered state over time.15 This disorder is referred to as “entropy” and is related to the mass and energy of the system involved. I speculated that increasing the mass and energy of the human system offers more opportunities for entropy to grow by promoting faster deterioration of our bodies through random damage to our cellular structures and organs.

Hayflick16 reported that a huge body of information supports the view that aging is related to random changes in molecular fidelity, and these undesirable molecular changes gradually accumulate until the body’s maintenance systems are overwhelmed. These undesirable changes are the product of time, radiation, thermal energy, free radicals, toxins, inflammation, bacteria, viruses and parasites.

To test the hypothesis that entropy increases faster in larger bodies, my associates and I collected data on the heights and deaths of various athletes, veterans, and famous people. Height was used as a surrogate for body size because it tends to be more stable than weight over one’s lifetime. (Height and weight are highly correlated.) The results showed a consistent decline in longevity with increasing height of about - .5 y/centimeter (cm).17-21

We also found that body weight without regard to height was also independently related to longevity [-.4 y/kilogram (kg)].22 (A body mass Index (BMI) of 21-22 kg/meter2 should be used as a baseline for predicting the loss of life with increasing body weight.)

There was general skepticism about the validity of the findings based on possible confounders or study methodology. In addition, a number of studies by other researchers conflicted with our findings. We then decided to explore the work of other researchers in relation to height, mortality and longevity. Extensive corroborative evidence was discovered, and some of it was based on millions of deaths, and a few studies tracked longevity from youthful ages to 100 y. We have had 20 articles or commentaries published in various medical, nutrition, and scientific journals. Chapters were also published in the International Encyclopedia of Public Health in 200823 and two other books on obesity research and nutrition. Another book, Human Body Size and the Laws of Scaling,24 was published recently on the global ramifications of increasing body size.

The author is aware of over 100 researchers that agree with one or more of the major points made in this paper. In addition, two recent publications25,26 have noted that many researchers and biologists support the thesis that shorter people live longer.

Most of our research is covered in Human Body Size and the Laws of Scaling,24 which includes over 1000 references. The following material highlights our findings, including conflicting research, centenarian heights, animal studies, and a variety of biological factors that are affected by greater body size. It should be kept in mind that we are discussing size differences within the same species and not across species where most research supports longevity benefits for larger animals, such as elephants and whales vs mice and rats.

Results

Between 1850 and 1950 nutritional scientists have focused on diets for babies, children and young adults to eliminate disease due to nutritional deficiencies, to lower vulnerability to infectious diseases and to promote a big, tall and strong population.27  Unfortunately, their achievements have created new health problems related to infancy, childhood and adulthood. A review of these problems follows.

Birthweight, rapid growth and obesity

Birthweight, obesity and long-term health. It is well established that our current obesity epidemic is tied to excess nutrition in terms of physical needs during childhood, adolescence and adulthood. However, excessive intrauterine nutrition and greater birthweight are also important contributors to obesity. For example, Martorell et al.28 reported that many studies show that lower birthweight adults are less likely to attain high BMIs compared to higher birthweight adults. In addition, most studies have found birthweight is positively correlated with adult height, weight and body mass index.2  A recent study by Mardones et al.29 reported that birthweight is linearly correlated with the risk of later obesity in children.  Other studies have shown that a rapid increase in weight during infancy is a precursor to later obesity.30 Oken and Gillman30 reported that virtually all studies have found that birthweight is positively correlated with adult body mass index. Thus, the common belief that a larger baby is a healthy baby is subject to reexamination, especially since some large studies have found that  mortality is independent of birthweight for a range of 2.5 to 4.5 kg.30,31

It is interesting to note that a large study found identical twins lived about 1.5 y longer than fraternal twins (82 y vs 80.5 y) and both lived a few years longer than singletons. Identical twins are lighter in birthweight compared to fraternal twins and both are substantially (~1 kg) lighter than singletons.32 (The birthweights of twins and singletons correlate with their adult heights and weights.)

Bradley33 has pointed out that in many parts of the non-developed world, low birthweight used to be common. Yet, these populations had very low levels of diabetes, cardiovascular disease,  and western-type cancers. In addition, Soltesz et al.34 reported that higher birthweight promotes future type 1 diabetes.

Song35 found Chinese adults subjected to the Great Leap Forward famine during gestation were stronger, healthier and had longer life expectancies than cohorts that were not exposed to famine. Song speculated that due to early mortality of some famine children, the survivors were inherently stronger. While malnutrition in childhood is harmful, perhaps the shorter and smaller body size of the famine survivors offset the negative aspects of intrauterine malnutrition. This would be especially true for children exposed to famine in the last trimester, who have lower birthweights and are at lower risk for later obesity.   

Birthweight is a function of three major factors: mother’s height, prepregnancy weight, and weight gain during pregnancy.30,36  Since maternal height and weight have been increasing over a number of decades, it is reasonable to expect that infants will continue to increase in weight during future decades compounding the obesity epidemic.

In summary, producing taller, bigger and fatter people is strongly related to increasing birthweight and overnutrition during childhood.  Thus, if the current trend towards overweight and obesity is to be reversed, public health measures need to focus on healthful nutrition, lower caloric intake, and avoiding higher birthweight as well as rapid growth during infancy, childhood and adolescence.

Rapid growth. Another common belief is that rapid childhood growth reflects good health and nutrition. However, a variety of species, such as lizards, trees and fish, demonstrate that rapidly growing individuals have lower long-term survival than slower growing individuals.37 A recent study38 found that girls who experienced menarche at 11 y of age had a 20% higher all-cause mortality compared to those who experienced it at 17 y. Another report found high growth rate and early age of puberty raised blood pressure in later life.39 Okasha et al.40 also reported that early menarche increased the risk of breast cancer.

Rapid growth and early menarche are due to increased protein and energy consumption.2,41  Fontana42 has observed that lower protein intake may play an important role in fighting cancer and promoting greater longevity. In addition, biologists are well-aware that slow growth is related to greater longevity. For example, Rollo43 reported that slow and protracted juvenile growth could produce large increases in longevity.

It is generally believed that lower growth in height and weight are indicators of poor nutrition. However, Marini et al.8  found that height and weight by themselves are not  reliable indicators of good nutrition. Experience from Okinawa and Hawaii supports their findings.44 For example, mortality declined among elderly Hawaiian Japanese men with a decreasing body size and caloric intake down to 4062 kilojoules (kJ) or 970 kilocalories (kcal) per day. However, below 4062 kJ, mortality started increasing.

Rapid growth in height and weight during early childhood has also been found to promote type 1 diabetes.34  And Betts et al.45 reported that rapid childhood growth, which leads to upward weight centile crossing, contributes to the increase in type 1 and 2 diabetes in the industrialized world (In addition, they found type 1 & 2 diabetes increased with birthweight). Cachera et al.11 also found that rapid childhood growth in weight and height was correlated with increased obesity and chronic disease in adulthood.

In recent years, a number of studies of industrialized populations have attributed a higher risk for coronary heart disease (CHD) and diabetes to accelerated or catch-up growth of lower birthweight infants.46,47 The WCRF/AICR report48 also noted that catch-up growth of low birthweight infants is correlated with the development of metabolic syndrome, cardiovascular disease and cancer. These children do not usually catch-up to their peer group in height,3 but overfeeding appears to program them for excessive weight in adulthood, leading to the various diseases of obesity. Yajnik49 also reported that when low birthweight children become tall, they are at increased risk for diabetes and cardiovascular disease. Wells47 believes this discordance between early smaller body size and later larger size places excessive loading on smaller organs designed to support lower food intake and lower body mass. Cameron and Demerath50 also noted that rapid growth leads to telomere attrition and promotes chronic diseases.

Based on recent research, Singhal et al.46 concluded that rapid growth promotes CHD and recommends that public health officials reconsider the policy of promoting rapid and early growth in children.

Who is more likely to become obese? In general, overweight and obesity are inversely related to income level for developed populations. In the past, taller people in higher socioeconomic (SES) levels were more likely to be thinner for their heights.51 In addition, Davey Smith et al.52 showed that men who were tied to manual labor during their entire lifetimes were shorter and heavier in comparison to those who lived in higher SES levels. However, Cohen et al.53 recently found that in America, taller people are getting fatter at a faster rate than shorter people. This new trend is probably due to a combination of increasing height and weight of mothers, long-term overnutrition, rapid growth and lack of physical movement.

Taller children are also at higher obesity risk. Freedman et al.54 found that children who were above the 85 percentile in height had 5 times the risk of becoming obese in adulthood compared to children who were shorter than average. In addition, taller children are more likely to experience early adiposity rebound, which increases the risk of early sexual maturation and later obesity.

Low birthweight (< 2.5 kg) children are also at risk, especially if they experience catch-up growth. In addition, smaller adults are at risk since serving sizes are standardized to the average population size. Thus they get more calories for their size unless they make a conscious effort to eat less; e.g., an excess of only 250 kJ/day (60 kcal/day) can add ~ 28 kg [60 pounds (lb)] over a 10-y period.

A major problem with the present approach to the obesity epidemic is concern that reducing the caloric and protein intake of children will reduce their growth and final height. It is obvious that western countries are both taller and have higher BMIs compared to non-developed populations who are shorter and free of obesity until they adopt western dietary practices. For example, healthy elderly and long-lived Okinawans were raised on nutritious but somewhat calorie restricted (CR) diets.55 In recent years, their children have grown compared to earlier generations as a result of changes in the food supply, including consumption of fast foods. These younger offspring are taller and bigger but now have more health problems and have lost their advantage in life expectancy compared to mainland Japan. Due to dietary and lifestyle changes, chronic diseases have also increased in Greece, S. Korea, and India as height has risen over the last 50 y.52

In summary, the trend towards increased overweight and obesity is affecting virtually all socioeconomic groups and is not likely to end without changes in some basic nutritional concepts and a concerted public health program that is more effective than countervailing food industry advertising. The Greek experience provides a warning of things to come. Forty-five years ago, the average Cretan male was fairly lean (BMI = 22.9 kg/m2).56 Now, 86% of the Cretan males are overweight or obese.  In addition, 79% of all Greek males are overweight or obese. Based on this evidence, it is highly probable that the US, UK and other developed countries will approach overweight or obesity levels of 100% in the next 50 y.

Cancer and height

Numerous studies have found a correlation between height and cancer, including reports by the World Cancer Research Fund/American Institute for Cancer Research14 and Gunnell et al. who reviewed about 300 studies on height and cancer.57  The WCRF/AICR report 58 ?? is based on a 5-y review of over 4400 papers on cancer and other chronic diseases and concluded that the evidence showing greater adult height is related to increased cancer risk is “... strong, consistent, and impressive.” While the risk of cancer for taller people is generally moderate, some types of cancers can reach higher levels, such as skin, prostate, breast, colon, and pancreatic cancers.52 (The risk of tall people contracting skin cancer is moderate to high, but the danger of death is relatively low.) Recently, Song and Sung59 reported that a positive correlation with height was found for total cancer and site specific cancers, such as the prostate, colorectum, breast, ovary, and uterine corpus. This 9-y study was based on 344,519 women subjects.

Coronary heart disease and height

Over 20 studies have found a negative correlation between height and coronary heart disease (CHD) and stroke.52 Most of these studies reported a 10 to 30% higher incidence or death for short people. For example, McCarron et al.60 found a 25% reduction in CHD risk for each 10 cm increase in height. The findings were based on 246 deaths. However, they also found that taller people had a higher risk of aortic aneurysm, which agrees with three other studies.  Findings showing short people have more CHD appear to reflect socioeconomic conditions, and the authors generally do not claim that it is shorter height per se that is the cause of CHD. Instead, low income and education, higher BMI, poor diet, smoking, excess alcohol intake, stress, and lack of a healthful lifestyle are generally attributed to the findings. Catch-up growth of smaller birthweight infants is also a factor since accelerated growth is related to CHD, and low birthweight adults are usually shorter than their peers.

Individual CHD or stroke studies often involve less than a few hundred deaths but some are based on a few thousand deaths. Many of these studies are generally based on developed populations and cover 5 to 20 y tracking periods. Risk adjustments for confounders are generally made although these adjustments may be crude and inexact.52 Adjustments almost always lower risk in favor of shorter people so that differences in incidence and mortality rates are reduced compared to taller people.

Seventeen studies have not found a significant correlation between height and CHD risk.19-24,52  Song & Sung59 and Song61 found that there was almost no difference in CHD between tall and short people in S. Korea, based on a large population of over 600,000 males and females. In addition, Hosegood and Campbell62  did not find a CHD-height trend among 1888 Bangladeshi women in a 19-y longitudinal study.

A number of researchers have found shorter or smaller people have lower CHD or heart problems; e.g., Allebeck, Chen, Krakauer, Mendall, Baron, Polednak, Samaras, Storms, and Elrick.20,52  In addition, Lindebergh found that 163 cm (5’4”) male Kitavans were free of CHD and stroke.52  Gupta, and Hameed also found shorter people have lower CHD within Indian and Pakistani populations.52

When shorter people migrate from poorer countries to prosperous countries, they generally have lower mortality from CHD. For example, Jewish and Italian immigrants to New York were the shortest immigrants and had a lower CHD mortality compared to the taller general population.52  Greek, Italian and Chinese immigrants to Australia also experienced lower CHD. The reasons for this lower mortality are probably related to their smaller size and reduced calorie, saturated fat, and protein intake while growing up in their original countries combined with improved living standards and medical care in their new country.

Before urbanization and industrialization, CHD, as well as other chronic diseases, were rare.14 In addition, many contemporary 20th century non-developed populations following traditional plant-based diets were generally free of CHD.  Contrary to the “taller is healthier” thesis, pre-industrialization and 20th century traditional populations were also relatively short and lean.

Powerful support for the “smaller is healthier” thesis comes from research on dog longevity.  Based on 350,000 dogs, smaller dogs have a strong advantage in terms of cardiac mortality compared to larger dogs.63  Bigger breeds have a cardiac mortality risk which is 6 times higher than that of small breeds. A possible explanation for this difference in mortality is that as the heart gets larger, its pumping efficiency declines.64  In addition, larger hearts are more likely to suffer from atrial fibrillation.65  It’s interesting to note that a study of retired football players found that the largest ones had 6 times the CHD mortality as the smallest.52 

Reasons to question findings that show shorter people have more CHD. There are a number of problems with contemporary findings indicating shorter people have more CHD. For example, based on the total US population, the incidence of CHD has increased in parallel with height since the beginning of the 20th C.  In addition, the WCRF/AICR14  pointed out that chronic diseases, including CHD, were rare before industrialization when people were shorter. In the US, before 1970, it was the taller well-off people that had more CHD compared to shorter working class people. After 1970, the situation reversed with working class people having higher rates of CHD. While both groups grew in height, the relative difference in height continued to exist. Therefore, other factors played a role in the reversal of risk for taller higher class people, such as reduced weight, more healthful diets and better medical care and living conditions.

It should be noted that height is just one of many factors that affect CHD risk; e.g., height by itself probably represents about 10-15 % of the total risk profile for short and tall people. Thus, weight, BMI, genetics, diet, exercise, etc. play a combined role that is greater than height alone.

Osika et al.66 found that taller people from the general population had lower risk of heart attacks compared to shorter people. However, when they focused on people in the lower economic brackets, tall people had a 40% higher risk of heart attacks compared to short people in the same economic bracket. This finding supports Holzenberger et al.13 in their observation that an improved lifestyle masks the health risks of taller height. And it explains why increasing life expectancy has paralleled increasing overweight and obesity. Certainly, improved lifestyle and medical progress deserve the credit for increased longevity, not increasing obesity.

When only developed countries are evaluated, the countries with the lowest CHD are relatively short, and the tallest countries have about 2 times the mortality.32  While not one developed country is free of CHD, a number of short populations in the non-developed world were free of this disease during the 20th century.52 They include the Cook and Solomon islands, New Guinea, Kalahari bushmen, Congo pygmies and Fiji Islands.52 Interestingly, since the 1970s, the Fijian population has grown taller and heavier due to dietary and lifestyle changes and has seen a substantial increase in CHD. Some critics challenge the use of non-developed populations to suggest that the cause of their low CHD rates is related to their shorter and lighter bodies. They argue that the low CHD of many non-developed populations is due to their lifestyle and diet. Of course, diet and lifestyle are important, but there are biological benefits related to smaller hearts and bodies, such as higher pumping efficiency, lower blood pressure, lower work load for the heart, and lower left ventricular mass and hypertrophy.30,64 

Table 1 provides a comparison among the US, Japan and Okinawa and illustrates the huge differences in age-associated death rates that exist based on increasing height.67  

       Table  1  Comparison of CHD and relative height for three populations

Population in order Age-Adjusted CHD mortality of increasing height   


  (Males) (Females)

Okinawa 33 (baseline) 15 (baseline)

Japan 51 (~1.5 X baseline) 43 (~ 3 X baseline)

US 193 (~ 6 X baseline) 177 (~12 X baseline)

Table 1 doesn’t prove that short people have low CHD due to their height, but it certainly shows that short height is not an impediment to attaining extremely low CHD.

While critics point out that studies which compare different populations are not the same as cohort studies within the same population, the facts are that many studies within the same populations have also provided data showing a decrease in CHD with decreasing height; e.g., Chen, Allebeck, Baron, Polednak, Krakauer and Samaras.52  While the previously mentioned papers by Song et al.61 and Song and Sung59 did not find a significant correlation between height and CHD, men 169-171 cm had a 16% lower risk compared to men ≥ 175 cm.61  Kannam et al.68 found, after adjustment for age and other risk factors, that short height did not significantly increase the risk for cardiovascular mortality in either sex. However, there was a nonsignificant decline in risk with increasing height among women.

Based on 1 million deaths, a California study found the two tallest ethnic groups in California had ~100% higher CHD mortality compared to the two shortest groups.32  In addition, a comparison of Northern and Southern countries in western Europe showed taller Scandinavian males had 100% higher CHD compared to shorter Portuguese and Spanish males.32  It was also found that Blacks and Whites in California were about the same height as Scandinavians and had about the same CHD mortality rate. In addition, the California Chinese and Japanese were about the same height as the Spanish and Portuguese males and had almost the same CHD mortality. The same relation between shorter and taller ethnic groups was also found in US nationwide data for Whites, Blacks, Native Americans, Latinos and Asians. See Table 2.

Figure 1 shows the increase in cardiovascular disease (CVD) among Native Americans.19  The mortality rate is given in deaths per 10,000 people per year. Native Americans have generally had very low CHD and stroke but this is now changing due to diet, obesity, and life style. However, until the last few years, Government data still show Native Americans have lower CHD and stroke than taller Whites and Blacks.

Davenport and Love52 evaluated the records of 2 million WWI military recruits and found that tall men had more heart problems. The tracking of the Japanese from Japan to Hawaii to California also showed a progressive increase in CHD mortality with increasing height.19  Lindebergh and Eaton have identified a number of populations which were free of CHD and stroke.52  These populations were also short.

New findings on telomere length and CHD also support the thesis that shorter people have less CHD. Telomeres tie the loose ends of chromosomes together. As somatic cells replicate during one’s lifetime, these telomeres get shorter and cell replications stop when telomeres get to a certain length. Terry et al.69  reported that a number of studies have found shorter telomere length is tied to greater cardiovascular disease. Since 

     Table 2   Age-adjusted coronary heart disease (CHD) mortality vs 

  height per 100,000 subjects/y (US National Data)

Ethnic group listed  in CHD  mortality rate

order of declining height Male Female

Blacks (same height as Whites) 408 292

Whites 333 218

Native Americans 220 138

Latino 214 146

Asian 198 121

% increase in mortality for

Blacks & Whites vs Asians 87% 110 %

shorter people have longer telomeres,70 this finding suggests that they have lower CHD. (Longer telomeres have also been found to correlate with increased longevity.69)

All-cause mortality and height

About 20 studies have found a negative correlation between height and all-cause mortality.52 As with CHD and stroke studies supporting an inverse relation between height and heart disease, the magnitude of risk generally varied from 10 to 30%. One of the biggest studies was Waaler’s52 which involved about 176,574 male and female deaths. However, this study did not account for SES conditions, smoking or BMI. In addition, it found that tall men between 70 and 85 y of age experienced a substantial increase in mortality compared to shorter men. A similar pattern was found for women at a somewhat younger age.  McCarron,60 Liao,71 and Kannam68 did not find a statistically significant correlation between height and all-cause mortality. In contrast, Song and Sung59 found a 7% decrease for women in all-cause mortality with each 5 cm increase in height. However, women who were 155-157 cm (5’1”-5’1.8”) had a 4% lower risk than the tallest women (≥ 161 cm).

Hosegood and Campbell62 followed the mortality of Bangladeshi women who were averaged 27.9 y at baseline. The women were tracked over a 19-y period, and height was not found to be an independent predictor of all-cause mortality. However, the lowest mortality was found for women in the height range of 148.0-151.2 cm. This height group had a 20% lower mortality compared to taller women (> 151.3 cm) and a 17% lower mortality compared to shorter women (144.1-147.9 cm). The shortest women (< 144.0 cm) had the highest mortality.

Many studies show short people have a lower all-cause mortality, such as Mori,72 Sear,52 Krakauer,52 and Willcox.52  For example, Mori72 evaluated the mortality of Japanese subjects by height and found that mortality increased by 6% with each 1 cm  increment in height. Thus, a 10% taller height would result in a 100% increase in mortality. In addition, a California study of five ethnic groups involving 1 million deaths showed a progressive decline in mortality with decreasing height with the Whites and Blacks having the highest mortality and the Chinese and Japanese the lowest.  A nationwide study by the US Government involved many millions of deaths and found Whites and Blacks had about twice the mortality as Asians.32   Native Americans and Latinos were in between these groups in height and mortality. An insurance study also reported that shorter men had lower mortality for the 60-69 y of age group.52  Short (but not the shortest) women 50-59 y of age also showed the lowest mortality. (Data were not provided for greater ages.) The total study involved 4.5 million men and women tracked over 20 y.

The previously mentioned Chinese famine study35 involved almost a million people. The all-cause mortality of pre-famine, famine and post-famine cohorts was tracked to 51 y of age. While the Barker theory and common sense would predict that the post-famine cohort would have the lowest mortality, it was the cohort exposed to famine that had the lowest mortality. The birthweights and heights of the cohorts were not given but there is a strong correlation between birthweight and adult height. 2,52  In addition, famine infants would have had low birthweights due to poor nutrition.35  Thus, adults born during the famine would be relatively short. Although their future mortality could increase above 51 y of age, a large Finnish famine showed no difference in mortality when researchers tracked the population into their eighties.35  Song speculated that the famine infants who were weak died off within a few years after birth, leaving a select cohort of stronger infants. Since small infants tend to be smaller adults, another explanation could be that reduced size and moderate food intake offset the negative aspects of malnutrition experienced during the famine.

Support for the Chinese findings comes from the Dutch famine, which found that adults (18 to 57 y) exposed to the famine during their fetal stage had a slightly lower all-cause mortality compared to those conceived after the famine.73 However, adults who were exposed to famine during the later part of pregnancy actually had a 25% lower all-cause mortality compared to those conceived after the famine. Mortality from cancer and other causes was also lower, but CHD was the same for these two cases. A possible reason for this finding may be due to the lower adult BMI associated with late-term famine exposure.

Immigrants often have lower all-cause mortality than the general population in their new country. Table 3 shows the substantial reduction in mortality for Mexican, Vietnamese, Chinese and Southern European immigrants to their new countries.52  These examples are supported by migration of Turks to Germany and Greeks, Italians and Chinese to Australia. The likely reasons for this reduced mortality are: (1) early energy-restricted plant-based 

Table 3   Shorter Immigrant all-cause mortalitya

Country of birth     Host Country    All-Cause risk level b

(all shorter than Male Female

host country)

____________________________________________________________

Mexico United States 0.57 0.60

Vietnam UK 0.64 0.56

China Canada 0.55 0.63

Southern Europe Germany 0.68c

a   Adapted from Table 5-3, Samaras T (ed) Human Body Size and the Laws of Scaling. 

      New York:  Nova Science Publishers; 2007.

b   Risk for general population = 1.0

c   Both sexes combined

nutrition and reduced growth in their original country and (2) improved health care and standard of living in their new country. A confounder could be due to immigrants being healthier than those who remained in their original country. However, this does not mean that they would be healthier than the host population. Another possible confounder is re-emigration of the elderly to their original countries but this has not been found to be a problem. 

Longevity and height

Most studies reporting taller people live longer really don’t measure longevity or life span. They usually track a group of people for 5 to 25 y and conclude that taller people live longer. Actually they measure all-cause mortality over a specified period for a specified age grouping, often with a baseline age of roughly 40 to 60 y. However, the previously mentioned Waaler study52 was one of a few that tracked the population into their 90s. Failure to track the whole cohort beyond their 70s can provide misleading results because most people in a cohort of people in their 20s at baseline will die after 70 y of age. In addition, the earlier mortality rate for a cohort that averages below 70 y is sometimes reversed at later ages. In addition, most studies fail to adjust risk for having mixed life experience in terms of economic class. For example, findings can be distorted if we compare taller men who have been in a higher class all their lives to shorter men currently in a higher income level but having grown up in a lower class. Mortality differences between classes can range from 100 to > 400% in favor of upper classes.

Another problem in contemporary studies is failure to adjust for increased life expectancy over the last 100 y.  Generally, shorter cohorts are older than taller ones.

Since a difference of 10 y in average age represents a 2.5 y increase in life expectancy for a younger and taller cohort, the shorter cohort is going to experience a higher mortality rate due to its greater age. For example,  if 5-y cohorts are used, the difference in age between taller and shorter cohorts could result in 60% higher mortality for the age range of 70-74 y simply due to the greater age of the shorter cohort.

A major reason the  “tall is healthier” proponents report that tall people live longer is:  taller, developed countries have longer life expectancies vs shorter, non-developed countries. When applied to countries of similar lifestyles and medical care, life expectancy is an indicator of longevity. However, when the life expectancy of developed countries is compared to non-developed populations, the results are misleading. For example, life expectancy of non-developed countries is sharply reduced by high infant, child and maternal mortality due to infections and medical problems that are normally avoided in the developed world. However, more elderly people live in the non-developed world than in the developed world, but this fact is not obvious in life expectancy data unless it is age categorized. And in the recent past, the elderly in the non-developed world died from basically the same problems that young people died from.74  However, in recent years 70% of the elderly in both the developed and non-developed worlds die from chronic diseases (e.g.; CHD, cancer and diabetes).75  These diseases are related to smoking, obesity, and the types and amounts of foods and beverages consumed.

The following will review longevity data, including data based on tracking cohorts to very old ages. Life expectancy studies are also included. Note that numerous animal studies have found smaller body size promotes greater longevity. Some of these studies are discussed in a later section.

Extensive findings support the “smaller is healthier” thesis; e.g., Table 4  lists some major studies showing shorter people live longer than taller ones.25,52  The loss of life per centimeter (cm) is often found to be  ~ .5 y/cm among highly diverse populations in the developed world. Also, US White male vs female populations show a - .5 y/cm, which is essentially the same as when short and tall males are compared.32   Figure 2 also shows shorter baseball players live longer than tall ones.21

A study of 40,000 WWII veterans who died between 57 and 84 y of age found that men who were 179 cm  (5’10.5”) had the highest life expectancy of about 77.8 y (unpublished report by Ferrie, J,  March 7, 2008). Men who were 152 cm ( 5’) had a lower life expectancy of 76.8 y and men 203 cm (6’8”) also had a decreased life expectancy of about 76.8 y. Heights at enlistment were used. A possible confounder could be that short and tall men with health problems were rejected from service. Military men usually live a few years longer than the general population because of this selection process. Whether differences in body proportions among short, average and tall men affected the results is *

not known; however, a stocky short person is at a health disadvantage compared to a tall, thin person.

In 1961, the World Health Organization found that 45-y old Greeks had the longest life expectancy in the western world. Males averaged 167.6 cm, which was shorter than central and northern Europe. Greeks from Crete were 1.6 cm shorter and lived even longer.76

A Spanish study,13 published in 1991, has generally been ignored by the “taller is healthier” proponents. This powerful study used mortality census data to track 1.3 million men over a 70-y period, starting when the men were between 20 and 30 y old. Their heights were obtained from military records. Adjustment for various confounders did not 

change the results (Fig. 3). A smaller Sardinian study25 also showed a trend line that was similar to that of  the Spanish study (Fig. 3 ). This study also tracked a male Sardinian cohort over a 70-y period to their deaths. Heights were based on military enlistment records.

A more recent study by Yates et al.77 tracked 2357 male physicians from a mean age of 72 y to over 90 y. The authors of the paper attributed the greater longevity of the survivors vs non survivors to smoking abstinence, blood pressure control, regular exercise and weight management. However, men who survived to 90 y were also .6 cm shorter,  1.3 kg lighter and .3 BMI points lower than non survivors. (Height and weight differences were statistically significant). The shorter survivors also had significantly lower risk of hypertension, diabetes, angina, cancer, CHD, stroke and Parkinson disease. Arthritis was the only disease that was higher in shorter survivors vs non survivors.

Data on elderly people from the American Cancer Society was analyzed for a relationship between height and longevity. Samaras and Heigh78 evaluated over 4500 men and women for the age groups of 85 y and 90 y. The taller 90-y old  males experienced a reduction in percentage of the population by 5% and the shorter 90-y old group increased by 5% compared to 85 y old groups. A similar pattern was found for women. Shrinkage did not account for the difference because the heights were determined at the study baseline 20 y earlier.  

Table  5  Life expectancy (LE) ranking for developed countries

  (a rank of 1 equals the highest LE)     

Top six countries in Six tallest countries in

order of LE Ranking (  ) order of LE ranking (  )

Andorra (located between France Sweden (7)

& Spain) (1)

Macau (located near Hong Kong) (2) Norway (20)

Japan (3) The Netherlands (28)

San Marino ( located in central Italy) (4) Germany (32)

Singapore (5) Finland (38)

Hong Kong (6) Denmark (47)

Average Rank:    3.5 Average Rank:   29

Table 6   Male-Female life expectancy and height differences

    for birth years of 1980-1983

Gender Height Life Expectancy 1 

Male 179.09 cm    71.2 y

Female 164.70 cm 78.4 y

Difference  14.39 cm - 7.2 y

% difference     8.7% taller males 9.2% lower LE

1 Life expectancies for 1980 and 1984 were averaged. Data for 1982 and 1983 

   were not available.

Among developed countries, the top countries in life expectancy tend to be relatively short compared to the tallest countries.  Table 5 compares the six countries with the highest life expectancy in the world to the six tallest countries in Europe.32  The six shorter countries have a ranking of 3.5 vs 29 for the tallest.

It is well-known that shorter women live longer than taller men throughout most of the world. Table  6 shows that men lost about - .5 y/cm compared to women. It should be noted that the males were 8.7% taller than females and they had an 9.2% shorter life expectancy.32  This is consistent with five previous examples published in 2002.17  The average for these previous examples was 8.0% greater height vs 7.9% reduced life expectancy. The difference in life expectancy between males and females is usually attributed to female hormones. However, Batallie et al79 reported that prospective studies have not found a relation between CHD and sex hormones.  It appears that the main elements for female longevity are related to smaller bodies, longer telomeres and a greater cell replication potential compared to males (telomeres are discussed later).70  Miller also found that men and women of the same height had about the same average life span.52  Animal studies have found similar results and are described in a subsequent section. Additional findings on the greater longevity of shorter people include Hawaiians black South Africans, the Greeks in the 1960s, and southern Europeans vs Northern Europeans.23 

Centenarians and height

According to the “taller is healthier” thesis, taller people live longer. However, if this were true, tall people should be disproportionately represented in the centenarian population. Unfortunately, they are virtually absent from people 100-y old and older. Roth80 reported that centenarians tend to be lean and short (adjusted for shrinkage). While tall people were much rarer in past centuries, there have always been tall people, including Presidents Washington, Jefferson and Jackson who were 185 cm (6’1) or greater. However, with advances in treating cancer, CHD and diabetes, more tall people are likely to reach 100 y in the near future.

The Okinawans are an interesting example of very short people with great longevity. They have the highest percentage (580/million) of centenarians in the world, and males average 148.3 cm (4’10”) and females 136.6 cm (4’6”).32  Adjusting for shrinkage would suggest that men were roughly 152 cm (5’) and women 142 cm (4’8) in their youth. However, with changes in diet and lifestyle this advantage may change in the future.

Sardinians are also noted for having the highest percentage of centenarians in Europe.81  They are also the shortest people in Europe. As with Okinawans, this advantage could be lost with adoption of different dietary and lifestyle patterns; e.g., fast food is now being consumed in Sardinia.

A recent report on WW I centenarians found that most were of medium height, and both short and tall had a smaller percentage of representives.26  Specific heights were not available, but WW I military recruits averaged about 171 cm (5’7.5”). A possible reason for shorter veterans not doing as well is that many grew up in poor urban areas that were unsanitary, congested and centers for communicable diseases. In addition, malnutrition and sickness would have produced shorter and less healthy men compared to taller recruits from healthier rural areas.

Supercentenarians and height

While supercentenarians are very rare, some data on their heights are available. A sample of 10 supercentarians was provided by Robert D. Young of the Gerontology Research Group  [e-mail communication from Bartke, 12/29/08]. Nine of the supercentenarians were 140 cm to 161 cm (4’7” to 5’3.5”) and the tenth was a tall 173 cm (5’8”) woman. The average height for these 10 supercentenarians was 151 cm (4’11.6”). No weights were provided. Table 7 lists the heights of these 10 supercentenarians. In addition, George Francis died at 112 y and was described as never more than 45.5 kg (100 lb). He was rejected from the military because he was too short. 

Animal longevity and body size

Robust animal findings support human findings indicating that smaller configurations live longer. Rollo52 found that smaller body size was related to greater longevity in mice based on a meta-analysis of about 800 studies. Similar findings have found that small rats 

Table  7  Heights of supercentenariansa

Name Sex Height

J Calment F 150 cm (4’11”)

S Knauss F 140 cm (4’’7”)

M-L Meilleur F 150 cm (4’11”)

E Parker F 152 cm (5’)

B Farve F 140 cm (4’’7”)

C Huhn F 158 cm (5’2”)

J  Bertrand F 173 cm (5’8”)

C Mortensen M 161 cm (5’3.5”)

T Tanabe M 150 cm (4’9”)

G Frau M 147 cm (4’10”)

Average height All 152 cm (5’)

a Source: Robert Young e-mail Dec. 29, 2008. Converted to cm from inches.

Note: George Francis, not included in list above, died at 112 y and was 

described as never weighing more than 100 lb and rejected from WWI military

service due to his short height.

live longer than normal and giant size rats.82  In addition, extensive data on dogs has shown that small dogs live longer than medium size dogs, who live longer than big dogs.83  These studies also show that both height and weight are independent predictors of longevity.52

Among large animals, smaller horses tend to live longer than larger ones, genetically small cattle live longer than normal size animals, and the smaller Asian elephant lives longer than the African elephant. Exceptions exist, but extensive findings support the thesis that smaller animals within the same species live longer.

Compared to larger species, why do smaller species have shorter lives while the smaller configuration within the same species usually lives longer? There does not appear to be a definitive explanation for this paradox. However, bigger species may live longer because of their lower metabolism and heart rate due to the effects of scaling.84  Bigger animals also grow at a slower rate and over a longer period. In addition, the evolutionary process may have selected for an increase in the potential number of cell replications and improved cellular and DNA repair systems as animals get bigger. 

Biological factors related to height

A few biological mechanisms support the “tall is healthier” thesis. The principal observation is that greater height reflects abundant nutrition and a healthful environment during youth. Other factors include a lower heart rate and resting metabolism. A lower resting energy expenditure is a strong benefit although vigorous activity would offset this benefit because a taller person needs more energy in proportion to body weight for many activities, such as walking or climbing stairs. While most people view robustness and larger muscle mass as an indicator of good health, long living people do not support this configuration, and the healthy body types tend to be quite lean.14,80  In addition, women have less muscle mass but live longer. In contrast, many biological mechanisms support the “small is healthier” thesis. These are summarized next and are based on similar body proportions between short and tall people. (The order of listing does not indicate a ranking by importance to aging.)

Longer telomeres

Short people have been found to have more potential cell duplications in old age compared to tall ones.70  Thus, short people can replace defective or dead cells for a longer time compared to tall ones . In addition, studies have found that DNA telomere length is an indicator of both replication potential and greater health and future longevity, and shorter elderly people have longer telomeres. Note that men and  women are born with the same length telomeres, but men have shorter telomeres in adulthood due to their larger size (mainly greater cell numbers). More importantly, they need to maintain those additional cells over a lifetime. (Many billions of cells are replaced each day.)

Fewer cells and lower cancer risk

  A short or small body may have 40 trillion fewer cells compared to a tall one. Thus, the opportunity for contracting cancer is lower since many fewer cells are exposed to  carcinogens and free radicals. Okasha et al.40 reported that cancer increases with height, which  correlates with bigger body mass and more cells.

Lower generation of free radicals

. Shorter people are exposed to fewer free radicals produced by normal metabolism and exposure to radiation, cosmic rays, bacteria, viruses and toxins; e.g., Fewer  free radicals reduce damage to DNA, cell structures, proteins, fats and extra cellular  components.85  Fewer free radicals also reduce cancer risk.

Most organs are larger in comparison to body weight

Most organs (except the heart, lungs and spleen) are relatively larger in shorter people86 and thus have a greater functional capacity, especially at advanced ages. Women also have relatively larger organs compared to men.

Lower DNA damage

. Short people have much lower DNA damage.86  For example, 18% taller people have up to 83% more DNA damage compared to shorter people. This is  probably due to rapid growth in childhood which diverts more of the body’s resources   from maintenance and repair to building new cells, tissues, bones and a bigger body. Reduced exposure to toxins, radiation, etc. would also reduce DNA damage in shorter  people.

Lower risk of cardiovascular disease

Shorter people have lower blood pressure and the heart works less per stroke in relation to body mass because of the shorter distances involved due to lower height and mass.84  They are also at lower risk of greater left ventricular mass, which is related to higher CHD mortality. In addition, the heart is more efficient at pumping blood through the body.64 Another benefit is lower risk of atrial fibrillation, which is related to greater heart size.65 

Lower exposure to toxins and bacteria

  Shorter people consume fewer solids and fluids. As a result they have lower intake of naturally occurring toxins, pesticides, antibiotics and food-borne pathogens.87  They  also experience fewer harmful byproducts of digestion. Their shorter colons also  reduce exposure to harmful agents due to reduced transit time.

Lower BMI for same body proportions

Taller people of the same body proportions have higher BMIs;84 e.g., a 20% taller person will have a BMI that is 4.2 kg/m2 greater than a shorter person. This would increase all-cause mortality by ~ 42%. This increase in mortality is probably due to undesirable increases or decreases in a variety of biological parameters, such as  shown in Table 8.86  A 24-y study on the impact of BMI on cerebral atrophy in women  found a 13 to 16% increase in temporal lobe atrophy per 1 kg/m2 increase in  BMI.88

Lower body temperature

 

While empirical data on lower body temperature of shorter people are scarce, the theoretical aspects make sense. Bigger land animals, such as elephants, are at high risk  for heat stroke because their surface area is  much smaller in relation to

      

Table  8   Undesirable increases and decreases in biological parameters for

      taller people of the same body proportions as shorter people

Undesirable increases Undesirable decreases

Insulin HDL

IGF-1 Sex hormone binding globulin

Blood pressure IGF binding protein-1

Glucose Adiponectin

Cholesterol, triglycerides                     LDLs, Apo A

Creatinine Heart pumping efficiency 

Cystatin C Maximum oxygen uptake

CRP  

Homocysteine

Fibrinogen

Apo B

Lp a

Left ventricular mass

Left ventricular hypertrophy

 their body mass. When active, they can’t dissipate the heat generated fast enough and body temperature rises resulting in a high incidence of heat stroke. Similar instances apply to  football players or other big athletes who may increase their metabolic rates by 10 to 20 times and thereby increase the heat load on their bodies compared to smaller  players.

Validity of Findings

In view of the preceding review, what conclusions on the validity of the findings can be drawn? Most epidemiologists and demographers believe that tall people are healthier and live longer, pointing to the correlation between greater average life expectancy and height of developed populations. In contrast many biologists and longevity researchers believe that shorter people live longer.25,26  After review of the research, the author believes that the data showing shorter people live longer is far stronger than opposing findings. The reasons for this conclusion are based on the following characteristics of the findings:

1. Findings favoring the “short or small live longer” thesis include a wide variety of studies; e.g., prospective and retrospective cohort, cross sectional, descriptive, ecological and experimental (various animals, including monkeys89 and humans).

2. A number of studies are consistent across a variety of specific ethnic populations, and other studies include a mix of ethnic groups within the studies.52  Findings within relatively homogeneous populations (baseball and football players) and heterogeneous studies52 are also consistent.

3. The loss of life per centimeter of greater height is highly consistent as shown in Table 4. The average loss in lifespan of .5 y/cm seems to be a recurring finding based on the data of several independent researchers, such as Miller, Krakauer, Polednak, Sarna, Topinard  and Samaras.52  In addition, Samaras32 found that American males lose .5 y/cm difference in height compared to women. While females live longer than males in virtually the entire world, the -.5y/cm does not seem to apply consistently to non-developed populations.

4. Some of the “shorter live longer” studies are based on very large numbers of deaths; e.g., 1 to > 8 million deaths within one country or population. In addition, several studies have tracked their subjects for 70 y or more years starting in young adulthood. .

5. Robust animal studies support the thesis that smaller people live longer. 

6. Few biological explanations support the “taller is healthier” thesis except for a lower resting metabolism and improved living conditions, which can apply equally to short people raised in comparable healthful environments from birth. In contrast, the previously discussed biological mechanisms (Table 8) explain why smaller bodies provide a solid foundation for extended longevity.

7. Smaller women live longer than men. While the common belief is that female hormones 

protect women from chronic disease, not all scientists agree. It certainly doesn’t make sense that estrogen is a major protective factor since 40-50 y-old women whose estrogen levels fall to that of men90 still live longer. The great majority of adults die after 50 y of age. In addition, postmenopausal hormone treatment has been found to increase the risk of CHD and cancer in women. In several societies males and females have the same level of CHD which would indicate that estrogen is not the major factor in lower female CHD which indicates that estrogen is not the major factor in lowering female CHD. It’s also interesting to note that dwarf male mice live longer than normal size female siblings. This would not be likely if the males had higher rates of mortality from heart failure.

8. Tall aristocrats and upper class people have been with us for hundreds of years. Yet they aren’t the dominant group among centenarians and supercentenarians? Although average height people are found among centenarians, there is to date nothing equivalent for people over 183 cm to the 147 cm (4’10”) male and 138 cm (4’6.5”) female centenarians in Okinawa. 

In conclusion, hundreds of studies have shown that shorter people have lower cancer, CVD, and all-cause mortality and greater longevity.52,58 Differences in CHD and all-cause mortality are often 100% higher in taller people. While many studies have shown shorter people in developed countries have higher CHD and all-cause mortality, few studies show that tall people have greater longevity. In addition, a number of factors explain why shorter people have more CHD in developed countries. These include catch-up growth, discordance between infant and childhood body size, overweight in adulthood, early health problems that stunt growth, and lower socioeconomic status.

Nutritional considerations

It is clear that the western diet has had both good and bad effects over the last 100 y. Certainly, in the developed world, relatively few people go hungry. However, on the other side, we have exceeded the ideal nutritional requirements for our living style. Too many calories, nutrient deficient foods, and too much animal protein have promoted various chronic diseases.6,27  In addition, experimental and cohort studies involving humans and non-human primates support the health and longevity benefits of lower calorie diets (Fontana,75 Willcox,44 Coleman89 ). The 2007 report by WCRF/AIRC91 notes that energy restriction postpones the onset of cancer and other age-dependent diseases. For example, a longitudinal study found 80% of monkeys subjected to CR89 were alive after 20 y compared to 50% of the normal fed monkeys. CR also delayed the onset of heart disease, cancer, diabetes and brain atrophy. Since the study was started with adult monkey’s, reduced size due to CR was only related to lower weight. The ages of the monkeys ranged from 27 to 34 y, and the study is continuing to track the mortality of the monkeys that are still alive (the maximum life span is ~ 40y).

Some have a pessimistic view about most humans being able to follow such a stringent diet. However, a high bulk, low-calorie diet could be developed by the food industry which mimics popular foods without the calories, excess protein and undesirable substances. The diet would thus satisfy the normal human appetite in spite of a 30% reduction in calories. Of course, a basically plant-based diet would be much preferred for those who could adapt to a very low calorie diet. However, caution is needed in following CR since an already thin person could reduce his/her weight to below a BMI of 18.5, which is generally believed to be the lowest acceptable value for good health. Care is needed to assure adequate protein, B-12 and other nutritants.

Protein is certainly an essential macronutrient and has been favored by many health professionals. However, a growing amount of evidence indicates that excess protein has many harmful ramifications. Fontana,75 Campbell6 and others have found that protein promotes cancer, other chronic diseases and aging. Most of us eat too much protein, and animal protein has a number of negative aspects. It increases levels of growth hormone, insulin-like growth factor -1 (IGF-1) and insulin and promotes a number of cancers.  Campbell and Campbell6 has researched the impact of protein, especially animal protein, on health and concluded that while it produces taller, bigger bodies, it also increases chronic diseases and reduces longevity. Fontana,42 Lopez,92  and Cameron and Demerath50 have related increased protein to cancer, chronic diseases, reduced longevity, hip fractures, and osteoporosis. In addition, a high-protein diet increases insulin and insulin resistance which are related to chronic diseases and reduced longevity [Masternak,93 Bartke94].

Fontana et al.42 found that reduced protein intake in humans lowered IGF-1 levels and may be an important factor in reducing cancer and increasing longevity. Early childhood introduction of protein from cow’s milk is also related to type 1 diabetes.34  A recent theoretical paper on the Second Law of Thermodynamics and human aging found that protein was more likely to increase body entropy (disorder) than carbohydrates and fats.95

The mass production of animal products has both health and environmental ramifications.  Cannon7 reported that mass production of animal food is not sustainable over the long run. These systems consume too much energy, destroy ecosystems, contaminate the land, and promote warming of the planet. Mass production of animal foods also creates huge increases in fat and saturated fat, which, along with animal protein, promote widespread obesity. Animal foods also require large amounts of water compared to plant foods; e.g., producing a kilogram of beef requires over 10 times the amount of water as growing a kilogram of wheat.

If the medical profession focuses on superior nutrition for the general public and reduces the emphasis on whether children grow up tall, medium or short, we will have a better chance of substantially reducing obesity and chronic disease. We will also avoid an economic breakdown due to unsustainable costs related to massive illness, initiated during early childhood. The WCRF/AICR report14 recommends a plant-based diet and a BMI range of 21-22.

In summary, much evidence indicates that plant-based, lower calorie diets can reduce chronic disease and increase healthy longevity.

Physical advantages of tall and short people

Our focus on sports that require tallness or big size have affected our perception of the physical attributes of shorter or average height people. However, the fact is that smaller animals are more athletic than big ones.96  Of course, there are benefits related to greater height and weight. Taller athletes make better basketball players and swimmers. They are also better sprinters and excel in a number of track and field events, such as high jumping and the shot put. And the strongest man in the world is not going to be a short person. However, short people have faster reaction times, can accelerate their limbs and bodies faster, have greater endurance, can rotate faster, and are more agile. They are also stronger on a pound-for-pound basis compared to bigger men or women and are outstanding weightlifters and boxers within their weight categories. Sports made for shorter people include gymnastics, marathon races, diving, figure skating, martial arts and certain skiing events. For example, Tara Lipinski was 142 cm tall and 34 kg when she won the world championship in figure skating. The short (163 cm) Tarahumara indians in Mexico are also noted for great endurance and commonly run 160 km races. (They eat a plant-based diet and are generally quite lean.) For a detailed analysis of the physical attributes of short and tall people, see Samaras.97

Intelligence and height

Many studies indicate that taller people are more intelligent as measured by IQ and academic performance. Differences in IQ are generally small and usually involve only a few points.98 Because we frequently read reports that taller people have higher academic attainment and earn more money, it is easy to see why much of the public believes this. The biological mechanism given for this greater cognitive ability is the fact the taller people have larger brains and therefore more neurons. However, most scientists don’t believe brain size within normal limits is related to intelligence. Based on the following evidence, it is obvious that studies showing taller people are more intelligent are measuring something else, such as economic or family advantages and higher expectations by parents and teachers.

Many of the world’s great scientists and artists have been average or below average in height.3 These include noble prize winners Einstein, Michelson, Millikan and McClintock, who averaged  from 150 cm (5’) to168 cm (5’6”).  Other examples include, Frank Lloyd Wright (170 cm/5’7”), Charles Steinmetz (122 cm/4’) and Buckminster Fuller (158 cm/ 5’2”). Among artists Picasso, Michelangelo, Juan Miro, and Tom Benton were 163 cm (5’4”) or less. In music, Mozart, Beethoven, Mahler and Stravinsky were 165 cm (5’5”) or less. Entrepreneurs include Andrew Carnegie (152 cm/ 5’), David Murdock (163 cm/5’4”), Onassis (165 cm/5’5”), and Ross Perot (165 cm/5’5”).  Many writers, such as Voltaire, John Keats, Jean Paul Sarte, Alexander Pope, and William Faulkner were also short.  Famous leaders include Churchill, Gandhi, Ben Gurion, Christ, Alexander the Great, and Madison. The Short Persons Support group99 lists 371 famous short people. Since most people over the last 3000 y were shorter than today’s averages, a detailed study of famous people would reveal an exceptionally long list of short or average height people.

Studies also show that Asians tend to have higher IQs than other races. It should be noted that the achievements of Japan following WW II, were made by people who averaged under 168 cm (5’6”). While the younger generation is taller, they are primarily the beneficiaries of the hard and creative work done by their shorter parents and grandparents.

Jewish immigrants to the US were one of the shortest groups entering the country about 100 y ago. Today, they are taller but still somewhat shorter than the general population in the US and other countries. Yet, they have produced a disproportionate number of high achievers in science, the arts, and medicine. In Europe, the Ashkenazi Jews have IQs that are 12 to15% greater than the taller general population.

If brain size is a driver for greater intelligence, then that would make women inherently less intelligent than men. However, recent academic achievements indicate that more women than men are graduating with advanced degrees.

The ancient peoples of Egypt, Greece, Rome, India and China were much shorter than people of today. Yet, their achievements reflect great intelligence and creative qualities. During the golden ages of England and Holland, people were also shorter than they are today. Shorter height and smaller brains didn’t seem to hamper them although the Cro-magnon people were considerably taller (males were about 183 cm), they apparently didn’t attain the brilliant achievements of Egypt, Greece, Rome, China, India, Elizabethan England or 16th century Holland.

From the 13th to the early 19th centuries, European height declined and remained short until later in the 19th and 20th century.2 Yet, the Renaissance period covered roughly from the 14th to the 17th century. Thus, literature, culture and art blossomed while height was declining.

Powerful support for the belief that being shorter or smaller is not significant in relation to intelligence comes from reports on the intelligence of dogs. Small, medium and big dogs seem to be equally represented among the smartest and dumbest dogs.98 In addition, within the same breed, such as poodles, toy, miniature, and standard size dogs are ranked as having the same intelligence. However, among schnauzers, the smallest breed ranks higher in intelligence than medium size and medium size breed ranks higher than the giant breed. In conclusion, if a larger brain was correlated with intelligence, it should be readily apparent from the very large variation in size among dogs since brain size scales to body mass and the weights of dogs range from 1 to > 90 kg.

Impact of height and associated body weight on resources, energy needs, fiscal costs and the environment

The non-health related ramifications of increasing height and body weight are also extremely important from the viewpoint of public health and the environment. A 20% taller US population was used to compute the increased needs for food, energy, water and resources as well as the impact of a greater output of garbage and carbon dioxide.100-102 It should be noted that a 20% increase in height assumes a proportionate increase in body width and depth dimensions. Most people fail to appreciate that a 20% increase in height will increase body surface area by 44% and weight or volume by 73%. For example, doubling the height of a 152 cm, 50 kg ( 5’, 110 lb) individual would result in a 400 kg (880 lb) individual when the same proportions are maintained.

A 20% increase in human height is large but not beyond the realm of possibility. For example, over the last 200 y, the Dutch have increased in height by over 20 cm. Twenty-eight percent of Dinaric Alps males are reported to be about 190 cm (6’3”).103

The combination of parental desires for tall children and genetic engineering, provide a  future scenario that can lead to a 20% taller world population over the next 100 y.

Table 9 summarizes the differences in consumption that will result if we continue the same lifestyle and most products are scaled to the taller US population.100-102

Recently, Edwards et al.104 computed the worldwide increase in carbon dioxide from .4 to 1 billion tons/y due to an increase in obesity.  Jacobson105 also computed the US auto fuel needs for an average increase of 11.4 kg (25 lb) in body weight to be 1 billion gallons/y. Another study106 found US airline fuel needs for a 4.5 kg (10 lb) increase in weight to be 350 million gallons/y and an associated increase in carbon dioxide of 3.8 million tons/y.

    Table  9   Increased consumption of a 20% tallera US population

Resource, trash, or fiscal costs Annual increase

Minerals, metals &  plastics 1.5 billion tons

Food 130 million tons

Farmland 180 million tons

Water                                                         86 trillion gallons

Energy                                                       40 quadrillion BTUs

Garbage (individual)                                 80 million tons

Carbon dioxide                                         3 billion tons

Fiscal costs                                               3 trillion dollars

a Assumes body build is proportional to shorter population

There are many other problems related to a population of larger body size people. Since we don’t get as strong in relation to our body weight, doctors, nurses, and nurses aids would have a lot of back problems or other injuries due to moving bigger patients. In addition, beds, chairs, toilets, and bathrooms would need to be enlarged to accommodate taller and bigger or fatter people. This would increase costs due to more sick leave and therapy. Also, bigger people are at higher risk for injury due to car accidents or falls.107

The cost of global heating and rising oceans due to increased pollution was not estimated, but could approach catastrophic proportions due to the loss of sea level communities and migration of displaced people to other areas. Since migrants would probably not be welcome into these inland communities, conflicts would arise with their attendant human, medical, environmental and economic costs.

The previous estimates are based on the assumption of a stable population size. If we experience both increasing numbers of people and greater body size, the numbers will be much larger.  Even if we don’t get any larger in body size and number, it is doubtful that we can survive a steadily increasing proportion of the GNP being spent on medical and health costs. If the proportion of current medical costs of roughly $2.5 trillion/y continues to increase because of following the same dietary pattern, our economic system is likely to collapse. Of course, radical reduction in the cost of energy and its associated pollution byproducts might prevent this collapse, but the risk is too high to ignore. The best solution would be to avoid future increases in height, weight and obesity through improved nutrition and reduced calories. If we continue to promote greater height as a desirable social trait, the parents of children that are naturally short will want to artificially increase their height. There would probably be millions worldwide who would desire some kind of treatment. What would be the cost? Perhaps some inexpensive treatment would be developed. However, based on today’s use of recombinant human growth hormone, it would cost roughly $52,000 per child for 2.54 cm of extra growth attained.3  If we assume 3 million children are treated in the US over a 10-y period, the cost would be $156 billion. Unfortunately, studies have not found a significant improvement in the quality of life due to a small increase in height and the treatment may have long-term health problems.

A final point. One could raise the objection that since shorter people live longer, they will increase resource consumption and produce more pollution. According to my calculations, the roughly 20% shorter population would still consume about 30% fewer resources and would also produce about 30% less pollution over their lifetimes. In addition, since shorter people would be healthier at older ages, they could work another 5 or 10 y before retiring.

Conclusion 

The traditional belief that shorter height is somehow less desirable than taller height is not based on systematic human and animal research, centenarian data, or biological mechanisms. There are many advantages to shorter, lighter bodies that are the product of healthful diets with moderate consumption of calories, fat and protein. Healthy shorter bodies are generally athletic, suffer fewer chronic diseases and are more durable than taller bodies. They also consume less food, energy, and other resources. Pritikin108 certainly was ahead of his time when he observed in 1979: “But we pay a high price for our increased physical stature! Both men and women are more likely to develop atherosclerosis younger, and die of strokes and heart attacks earlier, and be fatter in their middle age--though some won’t live that long.”

The diet that has made us taller, fatter and sicker needs to be viewed as a threat to our national security. Without this level of importance, the increasing costs of the obesity epidemic will eventually drain resources from education, research, public services, infrastructure, and military budgets. In addition, manufacturing of consumer goods will be severely impacted as discretionary spending is curtailed to accommodate medical costs. It will also become increasingly difficult to obtain lean and fit young people for emergency services, firefighting, the police and the military.

A population of somewhat shorter people resulting from substantially lower calories, fat, and protein intake starting at 2 y of age is less likely to suffer from overweight and obesity when a plant-based diet is followed. Of course, a substantial reduction in calories, fat and protein for children requires medical overview to assure adequate nutrition for slow but steady growth. If medical and government officials decide that a calorie restriction approach is not feasible, then a systematic program is needed to eliminate calorie dense beverages from our diet, reduce calories and saturated fat from school lunch programs, and severely limit high calorie snacks for children and adults as recommended by Popkin.109  As mentioned before, reduced calorie and improved nutrition must be initiated in early childhood. For example, Skinner et al.110 found that BMI at age 2 y was positively correlated with BMI at 8 y of age. In addition, the intake of fat and protein between 2 and 8 y of age was positively correlated with BMI at 8 y. In contrast, the percent of energy from carbohydrates was negatively correlated with BMI at 8 y.47  

Discordance between smaller birth size and later adult height and weight due to increased nutrition is certainly an important consideration in promoting poor adult health. However, larger infants that experience slower than normal growth and lower BMIs may experience superior adult health.

We need to change our thinking that taller height is a valuable attribute of humans. Tall, average, and short people can excel in virtually all human activities. Therefore, height should not be viewed as good or bad on an individual level. Using height as an index of health and well being was a reasonable technique for measuring nutritional levels early 20th century. However, today using height and rate of growth standards to determine health is a practice that propagates obesity and health problems. Height and weight for age need to be replaced by the use of biochemical parameters, individual nutritional analysis, and growth charts that allow reduced rates of weight and height gain.

The aim of medical and government authorities should be to de-emphasize increased height and body size as a desirable goal. Otherwise, with progress in genetic engineering, there will be a substantial increase in the height of future generations. However, the most important objective should be to promote a plant-based diet and public education on the health hazards of overnutrition during pregnancy, infancy, childhood and adolescence. Cannon27 stated that nutritional scientists need to develop recommendations to avoid chronic diseases in middle age in opposition to policies to grow big babies and big young people. These tasks will not be easy to accomplish but the alternative is a disastrous increase in obesity and chronic diseases that will have a heavy personal price as well as an insupportable fiscal cost to the world economy. Nutritional scientists need to develop recommendations to avoid chronic diseases in middle age in opposition to policies to grow big babies and big people.27

In conclusion, how tall is too tall? From a health point of view, when a taller and heavier configuration due to increased caloric, fat and protein intake results in reduced health and longevity, then we have gotten too tall. Based on the data in this report, It appears that several centimeters shorter than the average male and female in the United Kingdom, mainland Europe and the US would optimize longevity. A more definitive definition of when taller is too tall can be obtained by studying the heights of major centenarian populations. These include the relatively short centenarian populations of Okinawa, Japan, Sardinia, Italy, Akaria, Greece, Nicoya, Costa Rica and Loma Linda, California.111  New studies are needed to determine the optimum height and weight from each of these plant-based  longevity centers. 

Acknowledgements

Much appreciation is extended to Dr. Benjamin Alexander, Dr. Harold Elrick, Dr. Lowell Storms, Dr. Jonn Desnoes, Dr. Antonia Demas, Jim Price, Dr. Geoffrey Cannon, Dr. Richard Puetter, Dr. Elizabeth Rohwer, Dr. Colin Campbell, Dr. David Rollo, and Dr. Andrzej Bartke for their contributions and support over the years. They helped make this paper possible.

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