Secular trend in body size among college athletes.

Height and weight were compared across five birth decades (1850-1899) among 1,121 Harvard athletes who were lettermen in various sports. There were considerable differences in the magnitude of the secular trend among the sport categories (crew, baseball, football, track, ice hockey, and two or more sports). Comparing the 1890-1899 and 1860-1869 birth-cohort samples, football lettermen were 2.6 inches (6.6 cm) taller (p less than 0.001) and 20 pounds (9.1 kg) heavier (p less than 0.001). Crew lettermen were 2.6 inches taller (p less than 0.001) and 8.5 pounds (3.9 kg) heavier (p less than 0.05). For lettermen in other sports, changes in mean height and weight were smaller in magnitude. Differential selection for body size may explain the differences in the magnitude of the secular trend when analyzed by specific sport.     

Growth and skeletal maturation in British Columbia Indian Populations

Stature and skeletal maturation in childhood, mature stature, and calorie and protein intakes were studied in two populations of British Columbia Indians. Although mature stature was similar in both groups, one population (Anaham) showed delayed stature achieved for age and delayed skeletal maturity in childhood, compared with the other population (Ahousat). Analysis of growth data suggests that environmental factors are probably the predominant cause of the differences, which coincide with differences in nutritional status. Mean calorie intakes at Ahousat approximate or exceed the Canadian Dietary Standards, but those at Anaham are consistently below the standards for all age groups. Although mean protein intakes are well above the standards for all age groups, except teen-age girls at both reserves, they are consistently lower at Anaham than at Ahousat.     

The genetics of human fatness

Studies on the quantitative genetics of fatness are reviewed in the framework of the twin, adoption-cohabitation, and familial aggregation methodologies. Low to moderate heritability of adult static fatness is evident. Somewhat less than one-third of the variation appears ascribable to genetic causes. Genetic factors may play a greater role in childhood fatness, especially during adolescence. Comparison of studies is made difficult by many methodological shortcomings. These include a rarity of studies of adult first-degree relatives “adulthood being the period in which fatness has the greatest health consequences”, different criteria of body fatness among studies, a lack of a full variety of genetic and adoptive relationships, inadequate sample sizes “especially in twin studies”, and unreported precision of fatness variables. Fatness change in the life cycle and the anatomical placement of fat are important modifiers of the health effects of obesity. Yet the genetics of these characteristics are little understood. Innovative statistical methods and study designs including path analysis, the family set method, and families of monozygous twins need wider application to the genetics of human fatness.     

Comparison of the increase in body size between 1899 and 1970 in a specially selected group with that in the general population

Height and weight data for varsity football players from 1899 to 1970 were analyzed for evidence of a secular trend in such a specialized sample. Recent football teams ('61–'70) are, on the average, 2.6 inches (6.6 cm) taller and 35.3 pounds (16.05 kg) heavier than the teams at the turn of the century (1899–1910). The estimated trend over the 70 year span was 0.37 inches (0.94 cm) per decade for stature and 5.04 pounds (2.29 kg) per decade for weight. Unfortunately, it is not possible to partition these trends and obtain separate estimates for the “secular” effects and for those effects that might be attributed to “recruiting practices.” The observed trend for stature in football players corresponds with the upper limit of the estimated range for adult secular trend data for stature from Western European countries, and is greater than that reported for American young adult males both in college and in the general population.     

Estimation of total water and fatness from weight and height: inaccurate for lean women

Mellits and Cheek have provided a regression equation which predicts total water, and by extension, fat, from weight and height of women. The equation has been used by many researchers as a convenient means to estimate fat when more complicated body composition estimation techniques are not possible. It is an essential component of evidence provide by Frisch for the critical fat hypothesis. The equation has not been validated on another sample, however, and has a large standard error. I test the Mellits and Cheek equation on five samples of young women, two of which show a normal range of heights and weights. The other three are athletic samples composed of lean women. In the normal samples mean fat percent determined by density (from underwater weighing) is closely approximated by the weight and height equation but not in the lean samples. When measured fat is regressed on estimated fat, correlations are low, and standard errors are high, suggesting that the Mellits and Cheek equation predicts poorly the body fat percentage of individual females. In summary, the Mellits and Cheek equation is moderately useful for the prediction of group means for body composition on samples with normal ranges of height and weight. It does not produce acceptable results on groups selected for extreme leanness or obesity. It is not recommended for fat prediction of individuals.     

Longitudinal analysis of adolescent growth in height,fatness, and fat patterning in rural South African black children

Adolescent growth in height, fatness, and fat patterning was investigated in a sample of 79 rural South African black children studied longitudinally from 6–18 years. Data were analyzed relative to peak height velocity (PHV) to identify the phenomenon of “compensatory” growth in height during adolescence and to describe changes in fatness and fat patterning. Compensatory growth following PHV was clearly observed relative to NHANES data for African-Americans in that Z-scores for height at the start of the adolescent growth spurt were greater than those at the end of the spurt. Statistically significant differences in fatness and centralization between males and females did not occur until about 2 years after PHV was attained. Centralization of fat occurred in both sexes but moreso in males. The lack of centralization in females was due to relatively greater triceps skinfold velocities. The rapid gain in post-PHV fatness in females may represent a physiological adaptation to an energetically sub-optimal environment, buffering the energetic costs of reproduction. © 1994 Wiley-Liss, Inc.     

Fatness and skeletal maturity of Belgian boys 12 through 17 years of age

Relationships between fatness and skeletal maturity are considered in a nationwide sample of 14,259 Belgian boys 12 through 17 years of age (The Leuven Growth Study of Belgian Boys). Absolute fatness was estimated from four skinfolds using the Drinkwater and Ross technique and from the sum of four skinfolds, and was related to skeletal maturity assessed by the Tanner-Whitehouse method (I and II). In addition, comparisons were made between the fattest 5% and leanest 5% of the boys at each age level. Correlations between the indices of fatness and skeletal age and relative skeletal age (the difference between skeletal and chronological ages) are positive and generally low, ranging from 0.12 to 0.39. They tend to decrease with age from 12 to 17 years. Comparisons between the extreme groups indicate that the leanest boys are more delayed in skeletal maturity, by about 0.8 years, than the fattest boys are advanced, by about 0.5 years. Stature data for the same boys are consistent with the skeletal maturity data and thus suggest that the size differences between the extreme groups are due in part to maturity differences. Over the age span 12 through 20 years, the leanest boys are reduced in stature by about – 1.2 standard deviations, while the fattest boys are larger in stature by about +0.6 standard deviation units. The size differences, however, persist after skeletal maturity is attained so that there may be a specific role for fatness in influencing statural growth.     

Attained Weight,Stature and Weight/Stature Index for Egyptian Children Aged 6–18 Years. Cairo Area, 1980–1982

Data on body weight, stature and weight/stature² index of 1351 males and 770 females comprising a sample of Egyptian children from Cairo area aged 6–18 years have been presented. Body weight and stature were found to be higher than similar information from a nation-wide sample studied during the early sixties. Besides, there were differences in ages of the maximal increments between the present and previous national study that denote comparatively earlier occurrence of puberty spurts in weight and stature of Cairo children nowadays. However girls after puberty were found to be of lighter weight at present.     

Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea

The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.     

山东省儿童青少年生长发育20年变化趋势

为了解近20年来山东省儿童青少年生长发育的变化趋势, 本文利用山东省1985年、1995年和2005年学生体质调研资料, 分析了7—18岁儿童青少年生长的长期变化。20年间, 7—18岁身高平均增长6.27cm(城男)、5.02cm(城女)、7.62cm(乡男)、5.69cm(乡女); 体重平均增长9.97kg(城男)、6.02kg(城女)、7.96kg(乡男)、4.87kg(乡女)。BMI明显增长, 7—18岁平均增长2.57kg/m2(城男)、1.46kg/m2(城女)、1.71kg/m2(乡男)、0.93kg/m2(乡女)。发育水平上的城乡差别依然存在, 但身高的城乡差别逐步缩小, 体重的城乡差别明显扩大。下肢长指数(身高—坐高)的增长幅度大于坐高的增长幅度。总之,1985—2005年的20年间,山东省7—18岁儿童青少年在身高、体重、BMI和身材比例等方面都发生了较大变化。     

Short men in poor lands: The agrarian workers from southwestern Spain in anthropometric perspective

With a sample of heights of almost 60,000 men, born between 1855 and 1979 and recruited between 1876 and 2000, our work analyzes the nutritional gap between the agrarian and non-agrarian population in Extremadura, a Spanish region located among the poorest ones in Europe. The analysis reveals that this difference is not only statistically significant, but also tends to increase as the average stature of the active population grows. Among the causes of the agrarian height penalty, our article focuses mainly on the economic differences. However, the research also insists on the roots of these differences, especially those linked to the adverse physical conditions of the territory, the dynamics of the Christian conquest in the Middle Ages and the strong and persistent concentration of land ownership in the region. In short, this paper concludes that the anthropometric gap between agrarian and non-agrarian workers is due not only to economic causes, but also to geographical, historical and institutional reasons.     

The Bacon Chow study: Genetic analysis of physical growth in assessment of energy–protein malnutrition

Estimates of the prevalence of energy–protein malnutrition almost universally employ physical growth measurements. In this study we focus on this disease and the role of body size of relatives as mediators of responses in individuals to one type of nutrition intervention: supplementation of pregnant and lactating women. In this study, initiated by Dr. Bacon Chow and others in 1967, during gestation of a first infant a mother was untreated, while during the lactation of the first infant and the gestation and lactation of a second infant she was treated with either a calorie supplement or a placebo. Supplement–placebo group differences were sought in sibling and mother–child correlations in growth from birth to 30 months, in order to assess the role of heredity as a mediator of supplement effects. There were 108 pairs of siblings whose mothers had received a high-calorie–high-protein supplement as described above and 105 pairs of siblings whose mothers had received a placebo. Among the latter, sibling correlations for most measurements are statistically significant at birth, and of the same magnitude seen in previous studies (～0.5), while among supplemented siblings, birth correlations are unusually low and often insignificant. The sibling correlations in Rohrer's index (wt/L³) differed the most between groups (p < 0.01). Group differences in the sibling correlation tended to disappear over the first 2.5 years of life. Correlations between mothers and their second children in subscapular skinfold tended to be higher in the supplemented than in the placebo group, birth to 30 months. In both supplement groups mother–second child correlations for body weight were higher than mother–first child correlations, suggesting the occurrence of secular changes in the environment unconnected with the treatment. The results suggest that: (1) genetic analysis of components of anthropometric variation may be a more sensitive method than the more conventional comparison of group means in detecting supplement effects; and (2) infant relative weight (Rohrer index), particularly the addition of subcutaneous fat, may be more affected by maternal supplementation than growth in weight or length alone.     

Secular trend in the stature and weight of Mexican-American children in Texas between 1930 and 1970

Statures and weights for four samples of Mexican-American children in Texas, measured in 1929–1931 and 1968–1972, were evaluated for evidence of a secular trend. The age range was 6 to 18 years, with more complete data from 8 through 15 years. There is no secular increase in the statures and weights of 6 year old children, a small increase in 8 years old children, and a larger secular increase at 10, 12, 14, and 15 years of age. From about 9 or 10 years of age on, the more recent Mexican-American children tend to have greater weights for their heights. The magnitudé of the secular change per decade, however, is considerably smaller than rates for US black, white, European, and Japanese children. The estimated rates of secular change in stature for Mexican-American children approximate about one-fourth to one-half of the generalized rates for European and North American children offered by Meredith ('76) and Tanner ('77). Reasons for a limited secular trend in Texas Mexican-American children are probably bound to the matrix of lower socioeconomic circumstances, poorer health conditions, and marginal nutritional status.     

Cross-cultural correlations of childhood growth and adult breast cancer

International differences in breast cancer incidence and mortality, and studies on Japanese migrants to the United States, point to the importance of environmental factors, including diet and nutrition, in the etiology of breast cancer. Some studies have suggested that dietary patterns in early life are important to the long-term risk of breast cancer. Given that human growth is partially a function of early dietary intake, cross-cultural correlations between breast cancer rates and anthropometric variables measured at different times in childhood provide additional information about the association of early nutrition and cancer. In this study, the associations between food consumption and anthropometric variables, and childhood growth patterns (attained size at age) and adult breast cancer rates, were considered. Data from cross-sectional growth studies conducted during the years 1956-1971 on children aged 6-18 years were obtained for age-specific stature, sitting height, weight, triceps skinfold thickness, arm and chest circumferences, and biacromial and biiliac diameters. National food consumption data were obtained from the United Nations Food and Agriculture Organization (FAO) and socioeconomic status indicators from the United Nations Children's Fund (UNICEF). Cancer incidence data for the years 1972-1977 were obtained from regional cancer registries reported by the International Agency for Research on Cancer (IARC), and mortality data for 1978 were obtained from national cancer registries around the world. Significant correlations were seen between national food consumption data and childhood growth (attained size at age); between cancer incidence and age-specific stature (r = 0.68), weight (r = 0.59), triceps skinfold thickness (r = 0.78), and biacromial width (r = 0.84); and between mortality and age-specific stature (r = 0.77), weight (r = 0.75), and biacromial width (r = 0.78). In general, the correlation coefficients of the observed anthropometric variables with breast cancer increase with increasing age and become highly significant at ages 13-14 years, reflecting cumulative childhood nutritional intake.     

Body size and fatness of free-living baboons reflect food availability and activity levels

We used morphometric techniques and isotope-labeled water to investigate the influence of abundant, accessible food and resultant low activity levels on body size and fatness in free-living adolescent and adult baboons as compared to animals in the same population that experienced more typical, wild-feeding conditions. Females that had access to abundant food from a nearby garbage dump averaged 16.7 kg body mass, 50% more than their wild-feeding counterparts in adjacent home ranges. Little of the difference was due to lean mass: the animals with an accessible abundance of food averaged 23.2% body fat in contrast to 1.9% for the wild-feeding animals. Significant differences between feeding conditions were found for all measured skinfolds and for upper arm circumference but not for linear measurements. Differences between feeding conditions were less for males than for females, perhaps reflecting persistent effects of nutritional conditions during the first eight years of life before dispersal from the group of birth. The difference in fatness between feeding conditions was similar to the difference between humans with frank obesity and those that are considered lean, but in both cases the percentages of body fat in the baboons were considerably less than those observed in humans. In levels of fatness, the relatively sedentary animals resembled their counterparts in group-housed captive conditions. © 1993 Wiley-Liss, Inc.     

4 种不同脂肪源对太平洋鲑生长和体组成的影响

在日粮中添加11.5%的4 种不同来源脂肪饲养180 尾初始重约为110g 的太平洋鲑(Oncorhynchus spp.)于水泥池中56d。实验分4 组,每组3个平行池,每池15尾鱼。研究日粮中4 种不同来源脂肪对淡水养殖太平洋鲑生长性能、体组成与品质的影响。4 组脂肪源分别为鱼油(实验1 组)、大豆油(实验2 组)、大豆磷脂(实验3 组)和玉米油(实验4 组)。实验表明:(1) 实验各组太平洋鲑存活率相似,但大豆磷脂组的特定生长率显著好于鱼油组、大豆油组和玉米油组(P0.05)。大豆磷脂组、大豆油组和玉米油组的饲料效益显著好于鱼油组(P< 0.05); (2) 大豆油组、大豆磷脂组和玉米油组太平洋鲑肠系膜脂肪与肝脏脂肪含量不同程度低于鱼油组,而肌肉中脂肪含量不同程度低于鱼油组; (3) 实验各组太平洋鲑肝脏脂肪、肌肉脂肪和肠脂中总多不饱和脂肪酸组成基本相似,但玉米油组、大豆磷脂组和大豆油组太平洋鲑总n-3 多不饱和脂肪酸比例较鱼油组显著下降,而总n-6 系多不饱和脂肪酸比例显著提高(P<0.05);(4) 玉米油组、大豆磷脂组和大豆油组太平洋鲑血浆中脂肪分解酶、甘油三酯和高密度脂蛋白指标较鱼油组不同程度上升;(5) 实验各组太平洋鲑解剖组织学检查未见异常病理变化。实验结果表明,淡水养殖条件下,太平洋鲑日粮中脂肪以添加大豆磷脂的生长性能最好,大豆油、玉米油和鱼油效果相似,添加玉米油、大豆磷脂和大豆油均不影响太平洋鲑健康状况和品质。       

Nutritional status of Efe pygmies and Lese horticulturists

We assessed the nutritional status of 90 pygmies (Efe) and 211 members of a neighboring horticultural Lese in the Ituri forest in northeast Zaire. Clinical signs of iron and iodine deficiency were highly prevalent, but the frequency of these and other clinical signs of nutritional deficiency did not differ between the two groups. Infectious diseases such as yaws, cellulitis, and filiariasis were common. Absolute heights and weights of both Efe males and females aged 2–18 years were less than the 5th percentile of the National Center for Health Statistics standards. Weights for height of both groups were within the normal range. Weights and heights, expressed as percentages of the 50th percentile for age and sex, were significantly lower (P < .001) in Efe males and females than among Lese males and females, but weights for height did not differ significantly. Z-Scores of height and weight were also significantly lower in Efe males and females than among their Lese counterparts. The differences in weight and height, expressed either as a percentage of the 50th percentile or as Z-scores, were most apparent in older adolescents and persisted among adults. The normal weight for height among both populations indicated that acute undernutrition did not exist at the time of the survey. Despite comparable levels of adult fatness, measured by triceps skinfold thickness, heights of Efe males and females were lower than those of the Lese. These observations support the hypothesis that genetic differences account for the short stature of the Ituri pygmy. However, because the environments shared by the two groups are not identical and because other practices differ, nutritional effects cannot be excluded.     

Relationships between larval nutritional experience, larval growth rates, juvenile growth rates, and juvenile feeding rates in the prosobranch gastropod Crepidula fornicata

Planktonic larvae experiencing short periods of starvation or reduced food supply often grow and develop more slowly, have poor survival, fail to metamorphose, metamorphose at smaller sizes, or grow slowly as juveniles. In this study, we examined the impact of short periods of food limitation at various stages of larval development on larval and juvenile growth in Crepidula fornicata. In addition, we considered whether juveniles that were stressed as larvae grew poorly because of reduced rates of food collection due to impaired gill function. For 5 experiments, larvae were either starved for several days beginning within 12 h of hatching or were starved for the same number of days following 1 or more days of feeding at full ration (cells of the naked flagellate Isochrysis galbana, clone T-ISO, at 18×10⁴ cells ml⁻¹). In one experiment, larvae were transferred for 2 or 4 days to seawater with extremely low phytoplankton concentration (1×10⁴ cells ml⁻¹). In all experiments, larvae were returned to full ration following treatment. Control larvae were fed full ration from hatching to metamorphosis. When larvae reached shell lengths of about 900 μm they were induced to metamorphose and then reared individually at full ration in glass bowls, with phytoplankton suspension replenished daily. Larval and juvenile growth rates were determined by measuring changes in shell length (longest dimension) over time. Juvenile feeding rates were determined by monitoring changes in phytoplankton concentration over 2–3 h at the end of the growth rate determinations. In general, larval growth rates for the first 2 days after the resumption of feeding were inversely proportional to the length of time that larvae were starved. However, larval growth rates ultimately recovered to control levels in most treatments. Starving the larvae caused a significant reduction in initial juvenile growth rates (first 3–4 days post-metamorphosis) in most experiments even when larval growth rates had recovered to control levels prior to metamorphosis. Juvenile growth rates were not significantly reduced when larvae were subjected to reduced food availability (1×10⁴ cells ml⁻¹), even for treatments in which larval growth rates were compromised. Mean weight-specific filtration rates for juveniles were significantly reduced (p<0.05) following larval feeding experience in only one or possibly 2 of the 4 experiments conducted. Our data suggest that although larvae of C. fornicata may fully recover from early nutritional stress, the resulting juveniles may exhibit poor initial growth due to impaired gill function, reduced digestive capability, or reduced assimilation efficiency.     

Height, weight, and lines of arrested growth in young Guatemalan children

A cross-sectional study of height, weight and skeletal maturity as judged from radiographs of hand and wrist, of 1,412 children under seven years of age (694 boys and 718 girls) living in rural Guatemala was performed. Height and weight were compared to standards prepared by the Institute of Nutrition of Central America and Panama (INCAP). Skeletal age was assessed by the Tanner-Whitehouse and the Greulich and Pyle methods. All x-rays were read by the senior author. The children surveyed were significantly shorter and lighter than well noruished Guatemalan children. Differences were evident by age six months and at a maximum by age five years. Both methods showed skeletal age to lag behind chronological age so that the Guatemalan rural children mature at slower rates than either the British children or the Ohio, U.S.A., children, from whom the two sets of standards were developed. Children of both sexes with radio-opaque transverse lines at the metaphysis showed a consistent tendency to be shorter than children without such lines. Boys but not girls showed similar trends for weight. In general, the data are consistent with the view that the physical development in boys is more severely retarded by an adverse environment than that of girls.