Influence Body Composition Research Articles

Factors influencing body weight regulation.

As obesity is a major health problem for both the adult and adolescent populations of the United States there is an increasing need to understand basic mechanisms that control the body weight of an individual. Body fat content in adults is determined by energy balance status which is influenced by both food intake and energy expenditure. Current evidence suggests a dominant role for control of intake although chronic exercise and genetic factors will influence body composition. The hypothalamus appears to be the brain area responsible for determining food selection and intake although it is not yet clear how central mechanisms modulate peripheral feeding and satiety responses.

The five-level model: a new approach to organizing body-composition research

Body-composition research is a branch of human biology that has three interconnecting areas: body-composition levels and their organizational rules, measurement techniques, and biological factors that influence body composition. In the first area, which is inadequately formulated at present, five levels of increasing complexity are proposed: I, atomic; II, molecular; III, cellular; IV, tissue-system; and V, whole body. Although each level and its multiple compartments are distinct, biochemical and physiological connections exist such that the model is consistent and functions as a whole. The model also provides the opportunity to clearly define the concept of a body composition steady state in which quantitative associations exist over a specified time interval between compartments at the same or different levels. Finally, the five-level model provides a matrix for creating explicit body-composition equations, reveals gaps in the study of human body composition, and suggests important new research areas.

Factors influencing body composition during very-low-calorie diets

Apparent body composition changes with weight loss on very-low-calorie diet (VLCD) can depend on the method of fat-free mass estimation. In this report the implications of differences in measurement by direct versus indirect methods are examined. The nitrogen sparing and protein economy associated with ketosis is relevant and results of clinical trials with diets of varying composition are presented. The analytical findings of a multicenter, multimethod long-term VLCD study illustrate protein and metabolic conservation during VLCD. Protein losses, by total body nitrogen, over 10 wk dieting, independent of body mass index, were 4.75% of weight lost, as conservatively expected from obesity tissue reduction with no degradation of total energy expenditure. The implications of utilization of glycogen (water and potassium release) in interpretation of diet success and of body compositional change is evaluated. Evidence is presented that ultimate compositional changes with weight change may be individually specific and that body composition may be predicted from weight considerations alone.

Dietary Excesses of Leucine Influence Growth and Body Composition of Rainbow Trout

This study examined the hypothesis that a diet containing excess leucine may promote protein deposition in the body of rainbow trout. Diets were formulated with wheat germ meal and crystalline amino acids as major nitrogen sources. In Experiment 1, diets containing 1.1, 1.5, 2.2, 2.7, 3.5, 4.5, 6.0 and 6.5% leucine in wheat germ meal-crystalline amino acid diets were fed to fingerling rainbow trout. Diets containing up to 6.5% leucine did not inhibit weight gain or food intake. Body protein concentration tended to decrease as dietary leucine increased. In Experiment 2, fish were fed similar diets containing 3.3, 6.2, 9.2 and 13.4% leucine. After 10-11 wk of feeding, gross lesions including scoliosis, deformed opercula, scale deformities, scale loss, spongiosis of epidermal cells and scale regeneration were observed in 20% of the fish fed diets containing 13.4% leucine. High dietary leucine did not depress plasma valine or isoleucine concentrations. Therefore, the gross lesions could be attributed to a toxic effect of excess dietary leucine. Polyamine concentrations, which were used as a metabolic indicator for growth, were not significantly different in the tissues of fish receiving different treatments, thus supporting the hypothesis that increasing dietary leucine did not increase body protein deposition.

The effects of hormones, other pharmacological agents and nutrition on plasma triglycerides and carcass composition in lambs and steers

ABSTRACTThe effects of recombinantly derived growth hormone (GH), oestradiol-17β plus trenbolone acetate, clofibrate, melatonin and fasting on basal plasma triglycerides (TG) and TG entry rate were determined in wether lambs given lucerene/barley pellets ad libitum. Clofibrate was administered at 2 × 0·5 g capsules orally, GH (0·25 mg/kg live weight) was injected subcutaneously daily whilst oestradiol-17β, oestradiol-17β plus trenbolone acetate and melatonin were slow release implants (either 4 or 4·8 mg, 4 nig and 20 nig and 18 mg respectively) placed subcutaneously in the ear. Both fasting and oestradiol treatments raised basal TG levels without influencing TG entry rates, defined as the maximum rate of change of plasma TG 3 to 6h following a dose of Triton WR1339 of at least 0·2 g/kg live weight. Entry rates were similar to those previously reported for goats but were higher than those reported for sheep. Triton WR1339 used to determine entry rates was found to reduce food intake at all levels in some sheep despite reports to the contrary. Among the various treatments, only oestradiol-17β and trenbolone acetate influenced body composition as determined by chemical analysis of minced carcasses, resulting in an increased gain of carcass protein and decreased gain of carcass fat. Clofibrate, melatonin and Triton, if allowance is made for Triton-induced loss in food intake, had no clear effects on body fatness. Overall the effects of hormones on plasma TG appeared to be small and it seems improbable that plasma TG are involved in effects of hormones on fatness.

Effects of Growth Hormone on Body Composition in Adults

GH replacement therapy in GH-deficient adults has recently been shown to increase (normalize) muscle volume and decrease adipose tissue volume as measured by means of CT scan and skinfold thickness. Also in adults with acquired GH deficiency in adulthood, GH replacement has been shown to significantly influence body composition with an increase in lean body mass and a reduction in skinfold thickness. Preliminary results from an open long-term trial indicate that 12 months of GH substitution result in a further normalization of the muscle/fat ratio. The fluid-retaining effect, with a significant increase in extracellular-fluid volume demonstrated during GH administration to normal subjects, seems to be of little clinical importance if a replacement dose around 2 IU/m2/day is chosen for young GH-deficient adults. Long-term trials are needed to finally establish the indication of GH replacement therapy in GH-deficient adults.

Influence of preweaning food intake on body composition of young adult baboons

The hypothesis that infant overnutrition increases fat cell number and promotes obesity in the young adult primate was tested. Newborn baboons were fed similar volumes of Similac formulas with caloric densities of 40.5 (underfed, n = 8), 67.5 (normally fed, n = 12), and 94.5 (overfed, n = 12) kcal/100 g formula until 4 mo of age. Afterwards all baboons were fed the same diet until they were young adults. At 5 yr of age body composition, mean fat cell size, and total fat cell number were measured. Infant food intake did not significantly influence body composition or fat cell number in the 5-yr-old male baboons. Five-year-old female baboons, overfed as infants, had significantly greater body fat mass, percent of body mass that was fat, and mean fat cell volume compared with females that were underfed or normally fed as infants. There was no difference in total fat cell number between the obese baboons that were overfed as infants and the lean baboons that were underfed or normally fed as infants. Fat cell number was not associated with body fat content; males had more fat cells than did females. These results demonstrate that infant overnutrition in a primate species promotes obesity in young adult females by increasing primarily fat cell size and not fat cell number.

BODY COMPOSITION ACCORDING TO ADEQUATION OF STATURE OF ADOLESCENT OF DIFFERENT SOCIOECONOMIC LEVELS (SEL)

The influence of genetic and environmental factors on stature is well known. However it is difficult to study separately the influence of each factor. It has been shown that the lower SEL the higher influence of environmental factors. Nutrition and physical activities influence height and lean and fat body mass. We studied the composition of adolescents with normal and retarded height in different SEL. Children aged 10-16 years of both sexes, in Tanner stages II to V, were studied (n = 3211). Height for age (H/A), weight for height (W/H), lean and fat arm mass (LAM and FAM) were evaluated using NCHS tables; SEL, using Graffar modified scale and breast and genital development, using Tanner stages. Growth failure was diagnosed when H/A was less than 95% of adequate and normal stature when between 95 and 105%. Growth retarded boys of low SEL in early Tanner stages had less LAM and FAM. Boys of normal stature and low SEL had low LAM in the early and late pubertal stages but increased FAM in the early stage. Growth retarded girls in varying SEL exhibited no differences in LAM and FAM until the onset of puberty when those of low SEL exhibited increased FAM. Girls of normal stature and low SEL had low LAM and FAM in the parly stages and exhibited increased FAM in the late stages of puberty. We conclude that environmental factors can influence body composition.

FAT METABOLISM IN GROWING SWINE: A REVIEW

At birth, piglets have little body fat that can be mobilized. The influx of high-fat milk causes a rapid increase in body fat stores and a depression of lipogenic enzyme activity. Conversely, lipolytic enzyme activity increases after birth. Changing the fat intake of sucking piglets affects the amount of fat deposition. The length of the sucking period also influences body composition at weaning. Weaning produces a pronounced but temporary decrease in total body lipid, despite an increase in fat synthesis. The effect of weaning on lipolysis is not clear due to a lack of experimental data. During the growing period, fat continues to build up even though lipogenic enzyme activity tends to decline with age. The composition of the diet, the sex of the animal and genetic factors have all been shown to influence the rate of lipogenesis. Fewer reports have been published in which factors affecting lipolysis have been studied and the results are often less conclusive. However, the combined activities of lipogenic and lipolytic processes do not account for the large quantity of body fat found in growing pigs. Key words: Swine, fat, lipogenesis, lipolysis, diet, sex.

The Effect of Growth Rate on Fat Partitioning in Crossbred Ewe Lambs

The generally accepted view is that, in sheep and cattle, plane of nutrition (as indicated by growth rate) can influence body composition; the higher the rate of gain the greater the fatness at a particular live or carcass weight. However, exceptions to this view can be found which demonstrate that the effective protein: energy ratio of the diet can exert a considerable influence on the composition of live weight gain. Unfortunately most studies which have considered the effects of growth rate on composition (either directly or as a consequence of some treatment which resulted in different growth rates) have described their animals in terms of chemically determined protein, fat, ash and water. To assess the potential economic impact of different growth rates on body composition and the distribution of fat throughout the body requires dissection data, describing the animal in terms of lean, bone and individual fat depots. In this experiment the dissected composition of 44 Hampshire Down x Mule ewe lambs was determined in animals which had followed planned growth paths involving periods of high (H) and low (L) growth.

INFLUENCE OF THE FEEDING LEVEL ON GROWTH, FEED CONVERSION, PROTEIN EFFICIENCY AND CHEMICAL COMPOSITION OF JUVENILE EUROPEAN SEA‐BASS (Dicentrarchus labrax)

ABSTRACTThree experiments were carried out in which young European sea‐bass (average initial weight from 9 to 29 g) were submitted to different restricted food intakes based upon standard lots fed ad libitum.Growth always improved with increasing food intake, but tended to reach a plateau. Body and nutritional parameters improved when food intake decreased to 70–80% of the ad libitum level. Chemical body composition was rather constant. Only lipids were clearly affected by food intake, increasing with it.Food chemical composition greatly influenced body composition. When diets contained a high level of protein and a low level of carbohydrate, fat deposition in various parts of the body decreased significantly.

Body Composition in Suckling Rabbits1

Two hundred and one lots of suckling rabbits (103 of the Spanish Giant and 98 of the New Zealand breeds) were slaughtered at 0, 20, 25, 30 and 35 days of age and the energy, nitrogen, fat, water and ash contents of their bodies were determined. The rabbits suckled their mothers for 20 days. Afterwards they were offered four different starter feeds having two levels of acid detergent fiber (7 and 10%) and two levels of crude protein (17 and 20%). Weight was a good predictor of body composition, except for fat content. Age influenced body composition and was highly correlated to weight. This influence was significant (P<.05) for every body constituent, except ash, at all ages. New Zealand suckling rabbits had higher total fat content (P<.001), total energy (P<.01) , and lower water content (P<.01), than Spanish Giant ones of equal weight and age. Neither sex nor starter fed composition influenced body composition. Prediction of body composition based on fat, water, or protein contents was not better than that based on body weight.

Feeding the Premature Infant

Sir .—An article by Fomon et al advocating higher protein feedings for premature infants than those provided by human milk was published in theJournal(131:463-467, 1977). Please note the last paragraph on page 464. The authors discuss our work by citing reference 31 ( Ann NY Acad Sci 110:830-839, 1963), while they list another of our reports (reference 32) ( Am J Clin Nutr 25:1153-1164, 1972), among References and they do not discuss this one in the text. The results of our study as published in the American Journal of Clinical Nutrition are not as simple as they stated. Our report in the American Journal of Clinical Nutrition , 1972, showed clearly that electrolytes, their relative amounts in the milk, and the ratio of electrolytes (namely potassium) to protein influence body composition. Furthermore, it is not true that data have not been presented in sufficient detail... as they say on page 467, first

THE EFFECT OF SELECTED DIETARY LIPIDS, CARBOHYDRATES AND PROTEINS ON THE GROWTH, SURVIVAL AND BODY COMPOSITION OF Penaeusduorarum1

ABSTRACTSeveral protein, carbohydrate and lipid sources were incorporated into pelleted diets and evaluated for their effect on growth and survival of shrimp during a 12‐week study. Percentages of growth achieved using lipid sources of beef tallow, linseed oil, menhaden oil, corn oil and no lipid supplements were 61.8, 60.0, 52.9, 0, and 46.9, respectively. Percentage survival ranged from 64.7 for animals fed a diet containing beef tallow to for those fed a diet supplemented with corn oil. Among diets in which carbohydrates were tested, percentages of growth were 60.0, 25.0, 21.2, 18.8, and 12.9 among animals fed diets containing 40% starch, 10% glucose, 10% starch, 0% starch, and 40% glucose, respectively. Percentage survival ranged from 66.7 for the 40% starch group to 21.7 for the 40% glucose group. Among the several single protein sources tested, percentages of growth were 119.4, 78.1, 58.8, 48.6 and 29.7 for animals fed diets containing soybean meal, menhaden meal, shrimp meal, casein and corn gluten meal, respectively. Shrimp fed casein had a markedly lower survival rate than animals grown on diets having other protein sources.Freeze‐dried Artemia, clam and Tubifix worm added to a diet with menhaden meal as the protein source revealed that only additions of freeze‐dried Artemia produced significant growth above the control (percentage growth increases were 89.5, 41.9, 23.5 and 78.1 for Artemia, clam and Tubifix worm and the menhaden meal control, respectively). Survival was not significantly affected by any of the above supplements.Analyses of whole body composition of shrimp fed all of the above mentioned diets illustrated that some diets significantly influenced lipid and protein levels but did not significantly influence cholesterol levels. Shrimp fed a diet having no supplemented lipid had a significantly lower body lipid level (4.93%) than shrimp fed either diets containing corn or linseed oil (7.82% and 8.58%, respectively). Lipid supplements did not significantly influence body composition of protein. A diet supplied with 40% glucose caused a significant reduction in body lipid level (5.78%) compared to 10% glucose (9.03%) or 10% starch (8.67%). Likewise, a 40% glucose diet resulted in a significantly lower body protein level (70.41%) compared to percentages of 75.25, 75.11 for 10% glucose and 40% starch supplemented diets, respectively. Among protein supplemented diets, differences in lipid body composition were not significant but, shrimp fed a diet containing shrimp meal had a significant increase in body protein level (77.13%) in comparison to shrimp fed either menhaden meal or casein protein supplements (74.42% and 72.69%, respectively). Shrimp grown on diets containing menhaden meal supplemented with freeze‐dried natural foods did not have significant alterations in body levels of total lipid or protein.

Body composition of premature infants: relation to nutrition

Five comparable groups of premature infants, each consisting of six infants were studied. On the 6th and 28th days of life, body weight, total body water, and extracellular water were determined and intracellular water and dry body weight were calculated. During the 21-day interval, the infants were fed isocalorically at a rate of 120 kcal/kg per day one of the following milks: human milk, SMA S-26, Similac 0.67, Alacta. Analyses of variance were performed on the 6-day data. Analyses of covariance were performed on the 28-day with the 6-day data taken as the covariate. Differences between pairs of treatment means were tested. A stepwise, multiple linear regression and correlation program was employed to determine the influence of milk constituents on body composition. It was found that: 1) Diet had an influence on body composition. 2) There were no statistically significant differences in the final absolute dry weights. 3) There were statistically significant differences in the amounts of final total body water. 4) There were differences in the distribution of body water into the intra- and extracellular compartments. 5) Electrolytes, their relative amounts in the milks, and the ratio of electrolytes (namely potassium) to protein were found to influence body composition. The results and their interpretation are discussed.

Interrelationships among Energy Input, Body Size, Age and Body Composition of Sheep

Interactions of age, body weight and energy intake on the proximate chemical composition and energy value of the body were examined in 26 Shropshire, male-castrate sheep. Body weight at a given age was manipulated by imposing on a given animal one of two levels of energy input (averaging 278 and 421 kcal of gross energy/1 kg empty-body weight 0.73 per day). The amounts of body components at a given age were greater in sheep receiving the high intake of energy than in those supplied the low level. The relationships between the body components and body weight, however, were not different for the two energy input levels. Thus, energy input, within the range studied, did not influence body composition in a manner independent of its effect on body mass. In animals containing less than 31% of fat, the amounts of body components increased linearly with increasing body weight; above this concentration of fat, the weights of water and protein increased at decreasing rates and the amounts of fat and energy increased at increasing rates, as body weight increased. The overall best fit of the relationships between the body components and body weight was provided by the model, Y = a Xb. For these relationships, the R2 values for the predictands other than ash ranged from 0.939 to 0.982. The use of age in addition to body weight as the predictors increased the R2 values by only 0.002 to 0.019 over those computed between body weight alone and the various predictands. Thus, body composition in sheep was not related to prior energy intake, only slightly associated with age, but was chiefly associated with body weight.