Increased Body Fat Percentage Research Articles

Aging in humans: a continuous 20-year study of physiologic and dietary parameters.

The old adage, "You are what you eat," is not always reliable, as demonstrated in this mixed-longitudinal study of men that began in 1969. Mean values of percent body fat, total body potassium (TBK), and total serum cholesterol (SCHOL) did not show changes that correlated with any studied nutrient from repeated 4-day diet records. Mean blood pressure increased with increased body weight as age increased. High-density lipoprotein cholesterol decreased when polyunsaturated fat intake increased. The men had decreased mean height, TBK and increase in percent body fat as age increased. Food energy intake decreased equally from carbohydrates, protein and fat as age increased. Large standard deviations of mean values of measured parameters document heterogeneity of these subjects. A subset of 144 male cohorts was studied serially for 20 years in time-age, cross-sectional and longitudinal series. As they aged, height and TBK decreased (p < or = 0.05), percent body fat and blood pressure increased (p < or = 0.04) and SCHOL had no significant change. Intake of all nutrients decreased significantly (p < or = 0.03) longitudinally and with time, showing a time effect.

Effect of Defined Caloric Supplementation on Growth of Children With Renal Disease

The energy requirement of children with renal disease is unknown. Diets providing calories based on the Recommended Dietary Allowance for chronological age may or may not support normal growth in children with renal disease. Caloric needs were determined by indirect calorimetry in five children with renal disease. These children were then maintained on diets, supplemented with oral glucose polymers, designed to meet their measured energy requirements. After an average of 12.6 months on the study diet, four of five subjects exhibited catch-up growth as measured by a positive change in height and/or weight z scores. Despite caloric supplementation, not one subject exhibited increased percent body fat; increases in body weight consisted of both lean body mass and body fat. Variation in disease activity may also effect growth in children with renal disease. The energy requirement of children with renal disease is unknown. Diets providing calories based on the Recommended Dietary Allowance for chronological age may or may not support normal growth in children with renal disease. Caloric needs were determined by indirect calorimetry in five children with renal disease. These children were then maintained on diets, supplemented with oral glucose polymers, designed to meet their measured energy requirements. After an average of 12.6 months on the study diet, four of five subjects exhibited catch-up growth as measured by a positive change in height and/or weight z scores. Despite caloric supplementation, not one subject exhibited increased percent body fat; increases in body weight consisted of both lean body mass and body fat. Variation in disease activity may also effect growth in children with renal disease.

Seasonal production of rainbow trout, Oncorhynchus mykiss (Walbaum), in ponds using different feeding practices

Abstract. In temperate regions of North America, the culture of rainbow trout, Oncorhynchus mykiss (Walbaum), in ponds is constrained to the period mid-November to early April by water temperature. Feeding practice may influence production time. The effects of three feeding practices on growth and body composition of rainbow trout raised in ponds during a 142-day winter growth period were investigated. Feeding practices were (1) hand-feeding to satiation, (2) feeding according to a fish size/water temperature chart, and (3) feeding by demand feeder. Fish fed to satiation consumed 66% more diet than fish fed according to a feeding chart and 163% more than fish fed by demand feeders. Fish fed to satiation had significantly higher (P < 0·05) weight gain, harvest weight, specific growth rate, and protein gain with no significant increase (P > 0·05) in percentage body fat or feed conversion ratio (FCR) compared to the other two treatments. Survival percentage did not differ significantly (P > 0·05) between treatments. These data indicate that by using satiation feeding, marketable size rainbow trout can be produced in temperate region ponds without increases in percentage body fat or FCR.

Body composition in myelomeningocele

Body composition and measures of obesity were evaluated in 59 subjects with myelomeningocele (MMC), aged 0.3-29 y, by anthropometry and measures of body cell mass (BCM) and intra- and extracellular water (ICW and ECW), derived from total body potassium and deuterium-isotope dilution; these results were compared with reference data. Body composition was normal in preambulatory children with MMC. Beyond ages 3-4 y there was significant depletion of BCM and total body water, with maldistribution of water (increased ECW and decreased ICW) and increased percentage body fat above that expected for age and sex. These findings were more pronounced in females and in those with high lesions, and were less pronounced in those who remained ambulatory. These changes may result in metabolic and nutritional maladaption during stress. The relation of BCM, total body water depletion and increased ECW to decreasing ambulatory activity suggests that early nutritional and mobility programs warrant further study.

Increase in body fatness as a major determinant of changes in serum total cholesterol and high density lipoprotein cholesterol in young men over a 10-year period.

Serum cholesterol rises with age in most Western (and Westernized) populations. To identify causes of this rise, the authors studied 315 young Dutch men in 1976 in the district of Utrecht, The Netherlands, when they were aged 18 or 19 years, and again in various towns in the same region 10 years later, in 1986. These men formed the lower and upper quartiles of the distribution of changes in body mass index (weight (kg)/height (m)2) from 1976 to 1986 in a larger cohort of men representative of all Dutch men aged 18 or 19 years in 1976. In 10 years, mean serum total cholesterol (+/- standard deviation) had increased by 1.20 +/- 0.88 mmol/liter (46 +/- 34 mg/100 ml), and high density lipoprotein (HDL) cholesterol had decreased by 0.12 +/- 0.21 mmol/liter (4.6 +/- 8.1 mg/100 ml). The mean increase in body mass index was 2.7 +/- 2.5 kg/m2, and the mean increase in body fat percentage (assessed from skinfolds) was 3.3 +/- 4.6 g/100 g. The mean subscapular:tricipital skinfold thickness ratio--an indicator of body fat distribution--had not changed. In multiple regression analysis, the change in body mass index was the only significant (p less than 0.001) determinant of changes in serum total cholesterol; an increase of 1 kg/m2 in body mass index was associated with an increase of 0.20 mmol/liter (standard error, 0.02) in serum total cholesterol. Changes in body mass index and in smoking habits both contributed significantly toward explanation of changes in HDL cholesterol and in the HDL cholesterol:total cholesterol ratio. If smoking habits were adjusted for, HDL cholesterol decreased by 0.02 mmol/liter and the HDL cholesterol:total cholesterol ratio decreased by 0.012 (standard error, 0.001) for every 1 kg/m2 increase in body mass index. Changes in body fat distribution, as assessed by skinfold ratio, were not associated with changes in lipids. By interpolation, the authors estimated that for the full cohort of men, including the second and third quartile of body mass index changes, the mean rise in cholesterol had been 1.15 mmol/liter (44 mg/100 ml), of which 0.47 mmol/liter could be explained by the estimated rise in body mass index of 2.4 kg/m2. An increase in body fatness between ages 19 and 29 years is a powerful determinant of the rise in total cholesterol and the fall in HDL cholesterol occurring over that period of time.

Development of an animal model for investigating disparate myocardial effects of obesity and hypertension.

An experimental model for investigating the disparate effects of obesity and hypertension on the heart was developed by ligation of the aorta of male Sprague-Dawley rats made obese through ad libitum feeding. Experimental obesity was associated with an increased body fat and cardiac muscle mass, yet a normotensive systemic arterial pressure. Aortic ligation produced an elevated mean arterial pressure and resting heart rate, whereas body weight was similar to that of normotensive lean control rats. Obesity and hypertension together were associated with a significantly increased percent body fat, mean arterial pressure, and left ventricular mass compared with lean controls, whereas pressure and left ventricular weight were greater than those observed in rats with only obesity or hypertension. Cardiac adaptations corrected for body weight indicated that left ventricular weight increased as a function of body weight and body fat, but hypertension produced left ventricular adaptations independent of these variables. These initial studies indicate an additional contribution of hypertension to the left ventricular adaptations of obesity, and this model could therefore be used in future investigations concerning the cardiovascular effects of the simultaneous occurrence of these separate diseases.

Application of weight-height relations for assessing adiposity in a United Kingdom offshore workforce.

Weight (W), height (H), and skinfold thicknesses at biceps, triceps, subscapular, and suprailiac sites were measured in a United Kingdom offshore workforce. Weight and height were used to calculate W/H relations. The percentage body fat was estimated from skinfold thicknesses and the correlations of adiposity with the various W/H relations were evaluated. The significant increase in percentage body fat (%BF) with increasing age resulted in the development of age group specific regression equations relating %BF to the indices of W/H1.5 and W/H2 (body mass index or Quetelet index). Little difference regarding the qualities of these two indices were detected in terms of poor correlation with height and strong correlation with weight. Thus either may be used with similar levels of confidence. Comparison with other studies, however, would be more easily accomplished if W/H2 were used. In the absence of skinfold thickness measurements the W/H2 could readily be implemented during a routine medical and applied for the estimation of %BF in the offshore population provided that the appropriate regression equation were used and that the limitations of the technique are recognised. Percentage values for W, H, W/H relations, and %BF by age group are provided for comparison with other population studies.

Effects of training on weight, food intake, and body composition in aging rats

This study investigated the effect of endurance training on body weight, food intake, and body composition in female rats age 6, 15, and 27 mo. Animals underwent 12 wk of treadmill running. There was a significant increase in percent body fat associated with age. Training induced significant reductions in body fat which were of the same relative magnitude in all age groups. The 6-mo and 15-mo exercising rats significantly increased their food intake in response to the training stimulus; the 27-mo trained animals were unable to increase their food consumption relative to controls. It was concluded that 27-mo old animals are capable of changes in body composition similar to those of their younger counterparts, however, physiological mechanisms responsible for these shifts are age dependent. Older animals do not compensate their dietary intake for the increased energy expenditure of exercise as do the younger animals.

Body Composition and Other Physical Parameters as Determinants of Age at Sexual Maturity and Performance Efficiency in Dwarf Hens Divergently Selected for Body Weight

Hens in this study were produced from random breeding within lines (high, low, and control) of dwarf White Leghorns that had been divergently selected for four generations for 20-week body weight. Birds were weighed at 10 weeks of age and placed in individual cages at 18 weeks of age. Body weights, shank lengths, and egg weights were obtained at sexual maturity (day of first egg) and at 4, 8, 12, and 16 weeks after sexual maturity. Egg production was recorded during 28-day periods. Thirty hens/line were sampled at sexual maturity and at the above times after sexual maturity for body composition (percent fat, protein, moisture, and ash). High line hens showed increased percent body fat and reduced percent protein and moisture compared to low and control hens. Coefficients of determination (R2) for age at sexual maturity and body weight were small (R2 <.20) for high and control hens. There were no meaningful relationships between body weight or other physical measurements and sexual maturity in low hens. There were no significant relationships between body composition and age at sexual maturity in high and control hens. There was a strong cubic association (R2=.73; P<.001) between percent ash and age at sexual maturity in low hens, although the biological importance of this relationship was uncertain. Coefficients of determination between body weight and performance efficiency (egg mass per body weight) were small to moderate (R2 = .04 to .46) for high and control hens. The relationship of body weight to efficiency was nonsignificant for low hens, even though these birds were most efficient. The effects of body composition on performance efficiency were related to composition changes associated with selection for body weight.

Gonadal steroids in athletic women contraception, complications and performance.

Gonadal steroids are altered by the reproductive system's adaptation to conditioning exercise. Contraceptive options for the athletic woman include all measures appropriate for the sedentary woman. Barrier methods (always with spermicidal jelly) are the preferred choice. The cardiovascular risks, decreased aerobic performance, and shorter time to muscular exhaustion related to oral contraceptives make this a less desirable option. Potential complications from the steroid changes of intense exercise include: low oestrogen and progesterone with risk of loss of trabecular bone and early osteoporosis, and absent progesterone with low normal oestrogen levels associated with risk of endometrial or breast cancer. Therapeutic options for the amenorrhoeic or young athlete include supplemental oral calcium, cyclic oral progesterone, or possibly cyclic physiological oestrogen and progesterone. The anovulatory (usually older) athlete with regular menses needs cyclic progesterone. Medroxyprogesterone 10mg on days 16 to 25 of the cycle or for 10 days monthly can potentially prevent endometrial and breast cancer, give predictable cycles, improve trabecular bone balance and stimulate the return of ovulatory cycles. A practical approach to anovulatory infertility in the athlete includes a 10% reduction in exercise intensity and/or an increase in percentage body fat to 18 to 20%. Cyclic vaginal progesterone (25mg bid) can then treat short luteal phase cycles. With improved understanding of the hormonal adaptations to conditioning exercise, we will be better able to outline contraceptive and therapeutic options in the future.

Does the Lee obesity index measure general obesity?

Obesity, defined as increased percentage body fat, was correlated with the Lee index (weight 0.33/Naso-Anal Length) in three groups of adult rats. One group had been fed laboratory chow and served as controls. Another group had been made obese by feeding a palatable diet, and the third group made lean by a period of undernutrition during their suckling period. Although the three groups differed significantly in percentage body fat, there were no significant differences in their Lee indices. Further, the Lee index did not correlate significantly with percentage fat in any of the groups. It is postulated that the reason for the lack of correlation between obesity and the Lee index in intact rats is that length is a relatively weak predictor of fat free mass in animals of a similar age and nutritional history.

The Effect of Dietary Tryptophan and Niacin Levels on Broiler Breeder Pullets ,

A total of 1500 pullets and 300 cockerels were obtained at one-day of age and reared to six weeks of age on a commercial-type diet. At six weeks of age, birds were fed one of the following: Diets 1, 2 and 3 contained 0.150 percent tryptophan and no added niacin, 28 mg. added niacin and 280 mg. added niacin per kg. of diet, respectively. Diets 4, 5 and 6 contained 0.112 percent tryptophan and no added niacin, 28 mg. added niacin and 280 mg. added niacin per kg. of diet, respectively. All diets contained 2800 kcal. of metabolizable energy per kg. of diet and were fed for 21 weeks.The 0.112 percent tryptophan diets reduced body weight and percent body protein but increased percent body fat. Niacin levels had no effect on any of the pullet production parameters measured. However, at 21 weeks of age 280 mg. of added niacin in the 0.150 percent tryptophan diets restricted body weights of the males.