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PubMed2002

Factors that alter body fat, body mass, and fat-free mass in pediatric obesity.

PURPOSE: The purpose of this study was to quantify the effects of exercise treatment programs on changes in body mass, fat-free mass, and body fat in obese children and adolescents. METHODS: By using the meta-analytic approach, studies that met the following criteria were included in our analyses: 1) at least six subjects per group; 2) subject groups consisting of children in the 5- to 17-yr age range; 3) pretest and posttest values for either body mass, percent body fat, or fat-free mass (FFM); 4) used exercise as a mode of treatment (e.g., walking, jogging, cycle ergometry, high-repetition resistance exercise, and combinations); 6) training programs >or= 3 wk; 7) full-length publications (not conference proceedings); 8) apparently "healthy" children (i.e., free from endocrine diseases and disorders); and 9) published studies in English language journals only. RESULTS: A total of 120 investigations were located that addressed the issue of exercise as a method of treatment in pediatric obesity. Of those, 30 met our criteria for inclusion. Across all designs and categories, fixed-effects modeling yielded significant decreases in the following dependent variables: 1) percent body fat (mean = 0.70 +/- 0.35; 95% CI = 0.21 to 1.1); 2) FFM (mean = 0.50 +/- 0.38; 95% CI = 0.03 to 0.57); 3) body mass (mean = 0.34 +/- 0.18; 95% CI = 0.01 to 0.46); 4) BMI (mean = 0.76 +/- 0.55; 95% CI = 4.24 to 1.7), and 5) VO2max (mean = 0.52 +/- 0.16; 95% CI = 0.18 to 0.89), respectively. Significant differences were found as a function of the type intervention groups (exercise vs exercise + behavioral modification; P < 0.04); body composition assessment methods (skinfold vs hydrostatic weighing, DEXA, and total body water; P < 0.006); exercise intensity (60-65%, vs >or= 71% VO2max; P < 0.01); duration ( 30 min; P < 0.03); and mode (aerobic vs aerobic + resistance training; P < 0.02). Stepwise linear regression suggested that initial body fat levels (or body mass), type of treatment intervention, exercise intensity, and exercise mode accounted for most of the variance associated with changes in body composition after training. CONCLUSIONS: Exercise is efficacious for reducing selected body composition variables in children and adolescents. The most favorable alterations in body composition occurred with 1) low-intensity, long-duration exercise; 2) aerobic exercise combined with high-repetition resistance training; and 3) exercise programs combined with a behavioral-modification component.

Adolescent↗
PubMed1996

Body mass index in young adults: Associations with parental body size and education in the CARDIA Study.

OBJECTIVES: Associations of parental education, parental body size, and offspring's education with body mass index and 7-year change in body mass index were examined among participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study. METHODS: CARDIA is a study of coronary artery disease risk factors in 5115 Black and White persons aged 18 to 30 at baseline. Analyses of covariance were carried out with body mass index and change in body mass index as the dependent variables, and with parental education, parental body size, and participant education as the major independent variables. RESULTS: Father's body size was positively associated with participant's baseline body mass index among Black men, White men, and White women. Mother's body size was positively associated with baseline body mass index among all race-sex groups, and with change in body mass index among White women. Father's education was inversely associated with baseline body mass index among Black men and White women, and with change among White women. CONCLUSIONS: Parental education may influence body mass index and changes in young adulthood, especially among White women. Such associations may be both genetic and environmental and may be important for obesity prevention efforts.

Adolescent↗
PubMed1992

Predicting body weight and wither height in Holstein heifers using body measurements.

Relationships between body weight, wither height, and various other body traits, including heart girth, body length, and hip width, were studied using data from six experiments with 2625 observations. Body weight and wither height were regressed on the other body traits. Regressions of body weight including the linear, quadratic, and cubic effects of a single independent variable (heart girth, wither height, hip width or body length) indicated that each measurement would be useful in predicting body weight (R2 > .95); the regression of body weight on heart girth had the highest R2, followed by hip width. Similarly, regressions of wither height on heart girth, wither height, hip width, or body length, including linear, quadratic, and cubic effects, yielded R2 > .99. Regressions considering multiple traits as independent variables showed that the addition of a second body trait added little to the already high multiple correlations found with a single variable. In management situations for which body weight or wither height cannot be measured, various other traits can be used to estimate these body measurements accurately.

Animals↗
PubMed1998

Factors affecting body tissue mobilization in early lactation dairy cows. 2. Effect of dietary fat on mobilization of body fat and protein.

Twenty-two multiparous Holstein cows were fed either a control diet or a control diet plus 3% added fat (dry matter basis) to determine the effect of added dietary fat on body tissue mobilization and milk production. Body composition measurements were taken using the D2O dilution technique at -2, 5, and 12 wk postpartum. Cows fed added fat produced 2.7 kg/d more milk than did those fed the control diet alone, but milk production, milk composition, and dry matter intake were not affected by diet. The maximum amount of body tissue loss occurred between -2 and 5 wk postpartum when cows fed both diets mobilized 46 kg of body fat and 12 kg of body protein. Between 5 and 12 wk postpartum, only small changes in both body protein and body fat were observed. Even though cows fed added fat showed a tendency toward reduced body fat mobilization (66 kg for cows fed the control diet vs. 37 kg for cows fed the control diet plus added fat) and increased body protein mobilization (4.8 kg for cows fed the control diet vs. 19.5 kg for cows fed the control diet plus added fat), the differences were not significant. Apparent differences in fat mobilization between diets might have been due to initial body fat stores (159 kg for cows fed the control diet vs. 126 kg for cows fed the control diet plus added fat). Across diets, one unit of change in body condition score corresponded to about 55 kg of empty body fat. Supplemental dietary fat did not reduce body tissue mobilization in early lactation.

Adipose Tissue↗
PubMed2006

[Relationship between body condition (back fat thickness and body condition scoring) and fertility in dairy cows (German Black Pied/HF)].

It was the aim of this study to compare body condition scoring with ultrasonographic back fat thickness. Additionally, the relationship between back fat thickness and fertility, milk yield, number of parity and stage of lactation in dairy cows was examined. Body condition of 211 cows (German Black Pied/HF) was determined by means of ultrasonographic back fat thickness (BFT) and body condition scoring (BCS). The BFT and the BCS were measured at four different stages during the course of lactation (Time point 1 (T1) = 1.-3. d postpartum (pp); T2 = 40.-42. d pp; T3 = 90.-92. d pp and T4 = 130.-150. d pp). Number of parity, 100-day-milk-yield, incidence of ovarian cysts, incidence of acyclicity and fertility measures were recorded. There was a significant correlation between body condition scoring and ultrasonographic measurement of back fat thickness at the four time points (r = 0.68 to 0.74). Therefore, both methods were suitable to evaluate body condition. The number of lactations had an influence on body condition. At T1, the BFT in older cows was significantly higher than in younger cows (P < 0.05). At T3, the BFT in younger cows was higher than in older cows (P < 0.05). With regards to the stage of lactation, there was a significant decrease in body condition from T1 to T2 and T3. At T4, body condition increased, but did not reach the level of the postcalving values. In addition, cows with a high BFT at the beginning of lactation had a higher milk yield and a higher loss of body fat than cows with lower milk yield. Heifers compensated this loss of body fat significantly faster than older cows. Particularly at T3, body condition had an impact on fertility. Cows with a high loss of body condition between T1 and T3 developed significantly more often ovarian cysts than cows with low loss of back fat thickness. Cows with the lowest BFT at T3 had the longest calving to first service intervall and the highest 200-day-non-pregnancy index. In conclusion, our results suggest that there might be a certain relationship between body condition and fertility (delayed first service, ovarian disorders, reduced pregnancy results).

Adipose Tissue↗
PubMed1982

The effect of acute exercise on body density, body volume, and plasma volume.

In order to determine the relationship between reductions in body weight, body volume, and plasma volume, 22 track runners underwent exercises of various intensities and durations. The average mileage performed in the distance runs was 8.4 miles. The average caloric cost was 822 and 288 Cal for the distance and sprint activities, respectively. The overall range of energy expenditure was 100 to 1000 Cal. Before and after the workbout, body volume and density were determined by hydrostatic weighing on each subject. In addition, venous blood samples were analyzed for hematocrit (Hct) and hemoglobin (Hb), and the percent change in plasma volume (% delta PV) was calculated. Body weight and body volume decreases occurred in all subjects. Body density, percent body fat, and plasma volume were significantly altered only in the group of athletes undergoing distance runs. Body weight loss ranged from 0.3 kg to 2.0 kg and was correlated with body volume decreases (r = 0.91) and energy expended (r = 0.73). Body volume changes were related to the extent of density increases (r = 0.58), changes in plasma volume (r = 0.53), and energy enpended (r = 0.75). The % delta PV was significantly related only to changes in body volume. The results of this study indicate that acute exercise does affect body volume and thus the density and % fat determinations. These changes do not parallel closely the changes in plasma volume. The data suggest that for absolute accuracy, the state of hydration of the subject should be controlled prior to hydrostatic weighing. However, even in dehydration caused by prolonged distance running, the density measurement error is small and nearly within the methodological error of the hydrostatic weighing technique.

Body Composition↗
PubMed1996

Reversible large-body formation from nuclear bodies upon amino acid(s) starvation in T24 cells.

AP435 dot, a nuclear dot-like structure that is recognized by a monoclonal antibody AP435 MAb and that seems to correlate with perinuclear intermediate filaments, was identified as a nuclear body by double immunofluorescent staining with AP435 MAb and the nuclear-body-specific antibody alphaSp100 or mAb 5E10. In T24 cells, nuclear bodies usually appear as small entities with an apparent diameter ranging from 0.2 to 0.7 microm, and several to 20 or more of them are present per nucleus. After long culture without a change in the medium, however, nuclear bodies disappeared while one or more large doughnut-shaped bodies appeared, which had apparent outer diameters of 0.7-1.8 microm. When the medium was changed or medium components were added, large bodies disappeared and many nuclear bodies of normal size reappeared within several hours. Large-body formation was not related to the arrest of DNA synthesis, as revealed by double labeling with AP435 MAb and anti-cyclin antibody. Among the medium components, only an amino acid mixture induced the change from large bodies to nuclear bodies. Large-body formation was also observed in long-cultured HeLa cells. These results suggest that nuclear bodies reversibly aggregate or reorganized to form large bodies upon amino acid(s) starvation.

Adenocarcinoma↗
PubMed2003

Chemical body composition of 20 Thoroughbred foals at 160 days of age, and preliminary investigation of techniques used to predict body fatness.

AIMS: To determine the chemical body composition of Thoroughbred foals born in two consecutive years, and to investigate several techniques used to predict body composition in foals born in the second year, with particular reference to fat. METHODS: The chemical composition of 20 foals at around 160 days of age, born in two years, was determined. In vivo techniques to predict body composition were assessed in 23 foals born in Year 2, before and after euthanasia; 10 of these foals were used for chemical body composition analysis. Techniques to assess body composition in vivo included liveweight (LW), overall and regional condition scores, ultrasonic fat thickness measurements over the ribs and rump, linear measurements and bioelectrical impedance analysis. Correlations were determined between ultrasonic fat thickness, and bioelectrical impedance analysis, before and after euthanasia. Stepwise regression analysis was used to determine the relationships between in vivo techniques used to assess body composition and the chemical body composition of 10 animals. RESULTS: Foals used for analysis of chemical composition weighed between 220.5 and 260.0 kg before euthanasia. Fat content ranged from 5.5-13.0% of the partial empty bodyweight (LW less head, gastrointestinal contents, distal limbs and skin). Fillies had significantly more fat mass and percentage fat than colts (p=0.031 for both measurements). The mean chemical composition of the fat-free partial empty body was 73.2% (SD 0.6) water, 22.7% (SD 0.9) protein, and 4.1% (SD 0.4) ash. Most of the variation in the concentration of empty body water was associated with variation in the concentration of fat (p<0.001). The live animal overall condition scores were correlated with fat mass and concentration (p=0.006 and p=0.013, respectively; n=10). Condition score over the rib region was highly correlated with fat mass and fat concentration (p=0.004 and p<0.001; n=10). Ultrasound measurements taken 10 cm cranial to the tailhead and 4 cm from midline, used to assess the thickness of rump fat, were correlated with condition score (p=0.001), and explained 71% of the variation in body fat mass (p=0.002; n=10).Nearly 50% of the variation in fat-free mass and partial empty body water mass were associated with variation in the impedance indices calculated from length and bioelectrical impedance analysis measurements (p=0.023 and p=0.026, respectively; n=10). CONCLUSIONS: At around 42% of expected mature weight, fillies were significantly more fat than colts. Condition scores were correlated with partial empty body fat mass, and there was a trend for higher scores in fillies compared to colts. Much of the variation in water or protein mass of the partial empty body could be explained by variations in LW. CLINICAL RELEVANCE: Measurements of LW, rump fat and condition score are useful predictors of the chemical composition of foals at 5 months of age.

Journal Article↗
PubMed1981

Compartmental body composition of cancer patients by measurement of total body nitrogen, potassium, and water.

Quantitative measurement was made of body composition in patients with several forms of neoplastic disease. Total body nitrogen was determined by means of the prompt gamma neutron activation technique; total body potassium was measured with the use of a whole body counter. The mass and protein content of the muscle compartment and nonmuscle lean tissue were estimated by application of the technique of compartmental analysis. Total body water, determined simultaneously with the use of tritium label, provided a measure of lean body mass. From these data, the body fat can be inferred. The prompt gamma neutron activation and whole body counting techniques represent a considerable advance over the balance and radioisotope techniques used in earlier studies. The new techniques make possible sequential studies over prolonged periods of time with a considerable degree of accuracy. The loss of body weight by patients with solid tumors consisted primarily of the loss of muscle mass and body fat. Even in severe wasting, the patients appear to retain significant amounts of body fat. It is the skeletal muscle which is predominantly lost; the visceral life-supporting system is, to a considerable extent, spared. The nonmuscle tissue including the visceral fraction did not change in this study, and actually appeared to increase in size when comparison was made with the normal contrast population. The loss of total body water was slight in the cancer patients studied.

Adipose Tissue↗
PubMed2000

The paradox of low body mass index and high body fat percentage among Chinese, Malays and Indians in Singapore.

OBJECTIVE: To study the relationship between body fat percentage and body mass index (BMI) in three different ethnic groups in Singapore (Chinese, Malays and Indians) in order to evaluate the validity of the BMI cut-off points for obesity. DESIGN: Cross-sectional study. SUBJECTS: Two-hundred and ninety-one subjects, purposively selected to ensure adequate representation of range of age and BMI of the general adult population, with almost equal numbers from each ethnic and gender group. MEASUREMENTS: Body weight, body height, sitting height, wrist and femoral widths, skinfold thicknesses, total body water by deuterium oxide dilution, densitometry with Bodpod(R) and bone mineral content with Hologic(R) QDR-4500. Body fat percentage was calculated using a four-compartment model. RESULTS: Compared with body fat percentage (BF%) obtained using the reference method, BF% for the Singaporean Chinese, Malays and Indians were under-predicted by BMI, sex and age when an equation developed in a Caucasian population was used. The mean prediction error ranged from 2.7% to 5.6% body fat. The BMI/BF% relationship was also different among the three Singaporean groups, with Indians having the highest BF% and Chinese the lowest for the same BMI. These differences could be ascribed to differences in body build. It was also found that for the same amount of body fat as Caucasians who have a body mass index (BMI) of 30 kg/m2 (cut-off for obesity as defined by WHO), the BMI cut-off points for obesity would have to be about 27 kg/m2 for Chinese and Malays and 26 kg/m2 for Indians. CONCLUSIONS: The results show that the relationship between BF% and BMI is different between Singaporeans and Caucasians and also among the three ethnic groups in Singapore. If obesity is regarded as an excess of body fat and not as an excess of weight (increased BMI), the cut-off points for obesity in Singapore based on the BMI would need to be lowered. This would have immense public health implications in terms of policy related to obesity prevention and management.

Absorptiometry, Photon↗
PubMed2005

Body mass index and body fatness in childhood.

PURPOSE OF REVIEW: The prevalence of overweight, as assessed by a high body mass index (kg/m), has greatly increased among children and adolescents over the last three decades. Because body mass index is a measure of excess weight rather than excess body fatness, it is important to understand the ability of a high level to identify children who truly have excess adiposity. This review covers the measurement and classification of overweight and obesity, the expression of body composition data, and the relation of body mass index to adiposity. RECENT FINDINGS: Although adiposity has typically been expressed as percentage body fat, the use of the fat mass index (fat mass/height) and the fat-free mass index (fat-free mass/height) may provide more information. For example, body mass index differences among relatively thin children have been found to largely reflect differences in fat-free mass index, whereas differences among relatively heavy children are primarily due to differences in fat mass index. In addition, the ability of overweight to identify obese children is greatly influenced by the cutpoints selected for body mass index and adiposity. The use of inappropriate cutpoints, rather than the limitations of body mass index, may account for the frequently reported finding that many obese children are not overweight. SUMMARY: The use of fat mass index and fat-free mass index in expressing body composition data allows one to easily assess the contribution of each to body mass index. If appropriate cutpoints are used, a high body mass index level is a moderately sensitive and a very specific indicator of excess adiposity among children.

Adipose Tissue↗
PubMed2000

The estimation of body mass index and physical attractiveness is dependent on the observer's own body mass index.

A disturbance in the evaluation of personal body mass and shape is a key feature of both anorexia and bulimia nervosa. However, it is uncertain whether overestimation is a causal factor in the development of these eating disorders or is merely a secondary effect of having a low body mass. Moreover, does this overestimation extend to the perception of other people's bodies? Since body mass is an important factor in the perception of physical attractiveness, we wanted to determine whether this putative overestimation of self body mass extended to include the perceived attractiveness of others. We asked 204 female observers (31 anorexic, 30 bulimic and 143 control) to estimate the body mass and rate the attractiveness of a set of 25 photographic images showing people of varying body mass index (BMI). BMI is a measure of weight scaled for height (kg m(- 2)). The observers also estimated their own BMI. Anorexic and bulimic observers systematically overestimated the body mass of both their own and other people's bodies, relative to controls, and they rated a significantly lower body mass to be optimally attractive. When the degree of overestimation is plotted against the BMI of the observer there is a strong correlation. Taken across all our observers, as the BMI of the observer declines, the overestimation of body mass increases. One possible explanation for this result is that the overestimation is a secondary effect caused by weight loss. Moreover, if the degree of body mass overestimation is taken into account, then there are no significant differences in the perceptions of attractiveness between anorexic and bulimic observers and control observers. Our results suggest a significant perceptual overestimation of BMI that is based on the observer's own BMI and not correlated with cognitive factors, and suggests that this overestimation in eating-disordered patients must be addressed directly in treatment regimes.

Anorexia Nervosa↗
PubMedDate not supplied

Body size and body shape: perceptions of black women with diabetes.

PURPOSE: This qualitative study was conducted to explore perceptions of body size and shape in a group of black women with Type 2 diabetes. METHODS: Thirty-three black women with Type 2 diabetes participated in one of three focus groups to discuss perceptions about body size and body shape. Transcriptions of the discussion were analyzed for themes of participants' perceptions about their bodies, their ideas about body size and body shape, and personal and environmental influences on their preferences about size and shape. RESULTS: Participants preferred a middle-to-small body size but indicated that a middle-to-large body size was healthier. They also said that a large body size did result in some untoward social consequences. Participants preferred a pear-shaped body (a figure without abdominal adiposity). The three major influences on body image perceptions were children, parents, and the media. CONCLUSIONS: With these findings in mind, diabetes education programs that are geared for black women may benefit from the inclusion of key family members. Additionally, the importance of body image perceptions should be recognized in the design and implementation of weight-related diabetes education programs.

Adult↗
PubMed1986

Body weight and body image among college women: perception, cognition, and affect.

This study examined the relations between body weight and multiple parameters of body image in a nonclinical sample. Thirty-six female undergraduate students with stable body weights served as subjects; 12 were underweight, 12 were normal weight, and 12 were overweight, as determined using recent normative tables. Each subject responded to a general weight information questionnaire and to the Body-Self Relations Questionnaire, a standardized instrument assessing affective, cognitive, and behavioral components of appearance-related body image. A newly developed apparatus and procedure for estimating body size, the Body Image Detection Device, was utilized for perceptual and cognitive measures of body image. Each subject estimated and also subjectively appraised the width of her own body at five points and that of a realistic female mannequin. A caliper was used to record actual widths, and a standard laboratory scale and rule measured weight and height. The general finding of the study was that the perceptual, affective, and cognitive components of body image differed as a function of body weight, but the nature of the differences varied with the measure employed. The pattern of results for the perceptual measure suggest a cautious view of its reliability and validity. The multidimensional approach of our study, in marked contrast to earlier fractionated studies, offers a more integrated perspective on body image and provides new directions for future research.

Adult↗
PubMed2004

Effects of energy intake and body weight on physical and chemical body composition in growing entire male pigs.

Two experiments were conducted to determine independent effects of BW and DE intake on body composition and the partitioning of retained body energy between lipid and protein in pigs with high lean tissue growth potentials and when energy intake limited whole-body protein deposition. In a preliminary N-balance experiment involving 20 entire male pigs at either 30 or 100 kg BW, it was established that whole-body protein deposition increased linearly (P < 0.05) with DE intake at both BW. These results indicate that DE intake controlled whole-body protein deposition and that these pigs did not achieve their maximum whole-body protein deposition when fed semi-ad libitum. In the main serial slaughter experiment, 56 pigs, with a BW of 15 kg, were assigned to one of four DE intake schemes and slaughtered at 40, 65, 90, or 115 kg BW. Within DE intake schemes, DE intake was increased linearly (P < 0.05) with BW, allowing for an assessment of effects of DE intake and slaughter BW on chemical and physical body composition (carcass, viscera, blood). Between 15 and 90 kg BW, average DE intake of 16.1, 20.9, 25.2, and 28.8 MJ/d supported average BW gains of 502, 731, 899, and 951 g/d, respectively. The proportion of whole-body protein present in the carcass increased with BW and decreased with DE intake (P < 0.05), whereas the distribution of whole-body lipid between carcass and viscera was not influenced by BW and DE intake. A mathematical relationship was developed to determine the relationship between DE intake at slaughter (MJ/d) and chemical body composition in these pigs: whole-body lipid-to-protein ratio = 1.236 - 0.056 x (DE intake) + 0.0013 x (DE intake)2, r2 = 0.71. The data suggests that absolute DE intake alone was an adequate predictor of chemical body composition in this population of entire male pigs over the BW and DE intake ranges that were evaluated, simplifying the characterization of this aspect of nutrition partitioning for growth in different pig populations.

Animal Nutritional Physiological Phenomena↗
PubMed1997

Effects of body fat distribution on body size estimation accuracy among obese women.

UNLABELLED: Body fat distribution is a reliable predictor of the health risks of obesity. Abdominal obesity (AO) has been associated with various health complications whereas gluteal-femoral obesity (GFO) appears to be less hazardous. Body size overestimation, a type of body image disturbance, is found in a subset of obese persons. OBJECTIVE: The current study examined body size estimation accuracy as a function of body fat distribution. DESIGN: Cross-sectional, retrospective review of clinical records. SUBJECTS: 101 obese women (Mean age = 39.4) joining a weight loss program. MEASUREMENTS: Subjects provided body size estimates using a live video distortion procedure and were grouped into tertiles (AO; Mixed type obesity (MTO); GFO) on the basis of their waist-to-hip ratios. RESULTS: GFO women had significantly lower body size estimates and felt thinner than did AO or MTO women. In addition, more AO women (20.6% vs GFO: 8.8%) overestimated their body size by more than 15% whereas more GFO women (29.4% vs AO: 5.9%) underestimated their body size by more than 15%. CONCLUSION: Body fat distribution appears to be a mediator in body size estimation accuracy. These findings are discussed in terms of possible differences in perceptual and societal experiences among the groups.

Abdomen↗
PubMed1997

Total body potassium and body fat: relevance to aging.

Understanding the mechanisms that govern sarcopenia (depletion of muscle mass with age) may suggest ways to preserve lean tissue and functional capacity, and to maintain quality of life in the elderly. We investigated the body-composition changes in normal aging in a cross-sectional study of 188 healthy volunteers aged 20-89 y, which examines the differences in body cell mass and fat as a function of age. In aging, the assumptions of indirect body-composition-measurement techniques, such as the "constant" hydration coefficient of lean body mass or the "constant" density of fat-free mass, may not hold. Therefore, we selected body-composition-measurement techniques that are not sensitive to assumptions about the composition of lean tissue. Cellular mass, lean body mass, and fat were assessed "directly" by total body potassium (TBK) measurements and neutron inelastic scattering. Our results show that TBK content declines at a rate of 7.20 +/- 1.00 mg K.kg body wt-1.y-1 for females (r = 0.601, P < or = 0.001) and 9.16 +/- 0.96 mg K.kg body wt-1.y-1 for males (r = 0.710, P < or = 0.001). Body fat measurements by neutron inelastic scattering have shown a significant increase of percentage body fat with age for female volunteers between the ages of 20 and 50 y and a continuous increase for male volunteers throughout adult life.

Adult↗