Postpartum changes in body composition

Parity is associated with weight retention and has long-lasting and detrimental effects on the health of women. Previous studies have shown that increasing parity was independently associated with an increased prevalence of metabolic syndrome. Postpartum weight is made up of several components including uterine and mammary tissues, body water (intracellular (ICW) and extracellular water (ECW)), and fat. These components change in variable amounts postpartum, thereby distinctly affecting the interpretation of individual weight retention; however, it is unclear which components contribute to weight retention. The aims of this longitudinal study were to evaluate changes in body composition during the postpartum period and to investigate their effects on weight retention. This prospective study examined 41 healthy, pregnant women who gave birth at Korea University Guro Hospital. We measured body composition at 2 days, 2 weeks, and 6 weeks postpartum using bioelectrical impedance analysis. Weight decreased during this postpartum period (P < 0.001); the postpartum weight retention from prepregnancy to 6 weeks postpartum was 4.43 ± 4.0 kg. Among various body composition components, ECW, ICW, total body water, and fat-free mass (FFM) decreased postpartum. However, fat mass (FM) and visceral fat area, the components that experienced the greatest changes, increased postpartum. Our results demonstrate that the postpartum period is associated with a preferential accumulation of adipose tissue in the visceral compartment, even though overall body weight is decreased. Further studies are needed to evaluate the changes in body composition over longer time periods and their long-term effects on health.     

Plasma neuropeptide Y levels relate cigarette smoking and smoking cessation to body weight regulation

Loss and disproportionate gain of body weight often seen respectively in smokers and quitters are believed to be due to disrupted energy homeostasis induced by nicotine, the major constituent of cigarette smoke. Energy homeostasis is suggested to be regulated by the coordinated actions of peripheral adipose tissue derived leptin and the brain hypothalamic orexigenic neuropeptide Y (NPY). While the studies probing the role of leptin and NPY in weight modulating effect of nicotine have so far been inconsistent and based largely on animal systems, there is a paucity of data involving human subjects. Here we measured the plasma levels of orexigenic neuropeptide Y (NPY) and leptin in 35 non-smokers and 31 cigarette smokers before and three months after smoking cessation. Compared to non-smokers, smokers were leaner and had reduced NPY and leptin levels. Smoking cessation resulted in a significant weight gain and increased waist circumference accompanied by increased leptin and NPY levels. NPY levels were significantly correlated with body weight (r=0.43, p<0.05), BMI (r=0.41, p<0.05), and waist circumference (r=0.37, p<0.05), while leptin correlated with BMI (r=0.42, p<0.05) and waist circumference (r=0.39, p<0.05). Association of leptin with smoking status, but not that of NPY, was lost after controlling for anthropometric parameters. Weight modulating effect of cigarette smoke may thus involve its direct action on NPY, independent of leptin. Altered leptin levels in smokers and quitters may merely reflect changes in body weight or precisely fat mass.     

Pharmacological actions of the peptide hormone amylin in the long-term regulation of food intake, food preference, and body weight

The ability of amylin to reduce acute food intake in rodents is well established. Longer-term administration in rats (up to 24 days) shows a concomitant reduction in body weight, suggesting energy intake plays a significant role in mediating amylin-induced weight loss. The current set of experiments further explores the long-term effects of amylin (4-11 wk) on food preference, energy expenditure, and body weight and composition. Furthermore, we describe the acute effect of amylin on locomotor activity and kaolin consumption to test for possible nonhomeostatic mechanisms that could affect food intake. Four-week subcutaneous amylin infusion of high-fat fed rats (3-300 microg.kg(-1).day(-1)) dose dependently reduced food intake and body weight gain (ED(50) for body weight gain = 16.5 microg.kg(-1).day(-1)). The effect of amylin on body weight gain was durable for up to 11 wks and was associated with a specific loss of fat mass and increased metabolic rate. The body weight of rats withdrawn from amylin (100 microg.kg(-1).day(-1)) after 4 wks of infusion returned to control levels 2 wks after treatment cessation, but did not rebound above control levels. When self-selecting calories from a low- or high-fat diet during 11 wks of infusion, amylin-treated rats (300 microg.kg(-1).day(-1)) consistently chose a larger percentage of calories from the low-fat diet vs. controls. Amylin acutely had no effect on locomotor activity or kaolin consumption at doses that decreased food intake. These results demonstrate pharmacological actions of amylin in long-term body weight regulation in part through appetitive-related mechanisms and possibly via changes in food preference and energy expenditure.     

Birth weight and body composition in overweight Latino youth: a longitudinal analysis

To examine the associations between birth weight and BMI, and total body composition, in overweight Latino adolescents. Two hundred and forty-two overweight Latino children (baseline age = 11.1 +/- 1.7 years; BMI >or= 85th percentile) were measured annually for up to 6 years (2.6 +/- 1.4 observations/child, total 848 visits). Birth weight and history of gestational diabetes were obtained by parental interview. Visceral fat and subcutaneous abdominal fat were assessed by magnetic resonance imaging, while total body fat, total lean tissue mass (LTM), trunk fat, and lean tissue trunk mass were measured by dual-energy X-ray absorptiometry. BMI and BMI percentile were calculated using the Centers for Disease Control and Prevention age appropriate cutoffs. Longitudinal linear mixed effects (LME) modeling was used to evaluate the influence of birth weight on subsequent changes in body composition and distribution of fat across puberty. Birth weight significantly predicted BMI (P < 0.001), total trunk fat (P < 0.001), total trunk LTM (P < 0.001), total fat mass (FM) (P < 0.001), and total LTM (P < 0.001), but not subcutaneous (P = 0.534) or visceral fat (P = 0.593) at age 11 years. Longitudinally, as participants transitioned into puberty, birth weight did not significantly predict any of the body composition or fat distribution measures (P > 0.05). Birth weight is significantly associated with increased adiposity and LTM and negatively associated with trunk fat mass and trunk lean mass at baseline; however these relationships did not predict rate of change of any of the variables as the children progress through adolescence.     

Exercise and body composition

We assessed changes in body composition in 41 young adults who engaged in various exercise and/or training programs on ad libitum diets. Most of those who gained weight sustained an increase in lean body mass (LBM), and most of those who lost weight lost LBM as well as fat. The change in LBM was directly related to the change in weight, with a regression slope of 0.500. An analysis of published data confirms these findings and, in concert with our data, provides the additional information that the magnitude of the change in body composition in exercising individuals is influenced by body fat content, just as it is for nonexercising individuals.     

Effect of oral theaflavin administration on body weight,fat, and muscle in healthy subjects: a randomized pilot study

Theaflavins are reddish-colored polyphenols in black tea. To test the efficacy of theaflavin administration on body fat and muscle, we performed a randomized, double-blind, placebo-controlled study and investigated the effect of theaflavins administration on the body composition using of healthy subjects. In this study, 30 male and female Japanese were enrolled and participants were randomly allocated to receive placebo, theaflavin (50 or 100 mg/day), or catechin (400 mg/ml) for 10 weeks. The effects were evaluated using body weight, body fat percentage, subcutaneous fat percentage, and skeletal muscle percentage. Theaflavin administration significantly improved body fat percentage, subcutaneous fat percentage, and skeletal muscle percentage when compared to with the placebo. In contrast, there was no significant difference in all measured outcomes between the catechin and the placebo groups. The results indicate that oral administration of theaflavin had a beneficial effect on body fat and muscle in healthy individuals.     

Changes in body composition with weight loss: obese subjects randomized to surgical and medical programs

Objective: To assess changes in body composition with weight loss in obese subjects randomized to a laparoscopic adjustable gastric band surgical program or a medical program using a very‐low‐energy diet and orlistat. Research Methods and Procedures: Using body composition measurements by DXA, neutron activation for total body nitrogen, and whole body γ counting for total body potassium, we studied changes in fat mass, fat distribution, fat‐free mass, total bone mineral content, total body protein, and body cell mass at 6 (n = 61 paired) and 24 months (n = 53 paired) after randomization. Results: At 24 months, the surgical group had lost significantly more weight (surgical, 20.3 ± 6.5 kg; medical, 5.9 ± 8.0 kg). There was favorable fat‐free mass to fat mass loss ratios for both groups (surgical, 1:5.5; medical, 1:5.9). Changes in total body nitrogen or potassium were favorable in each group. A small reduction in mean bone mineral content occurred throughout the study but was not associated with extent of weight loss or treatment group. At 6 months, weight loss for both groups was similar (surgical, 14.1 ± 4.5 kg; medical, 13.3 ± 7.3 kg). The medical program subjects lost less fat‐free mass and skeletal muscle and had increased total body protein. The proportion of body fat to limb fat remained remarkably constant throughout the study. Discussion: Weight loss programs used in this study induced fat loss without significant deleterious effects on the components of fat‐free mass.     

Soy protein isolate in the presence of cornstarch reduces body fat gain in rats

The objective of the present study was to determine the combined effects of dietary protein and carbohydrate sources on total body energy and protein and fat gains as well as on plasma insulin and glucose and tissue lipoprotein lipase activity in male Sprague-Dawley rats fed semipurified diets for 28 days. The diets varied in both protein and carbohydrate sources, namely, casein-cornstarch, casein-sucrose, soy protein isolate (SPI)-cornstarch, SPI-sucrose, cod protein-cornstarch, and cod protein-sucrose. When SPI was combined with cornstarch, lower total body energy and fat gains were observed compared with the combination of either casein and sucrose, casein and cornstarch, or SPI and sucrose. Plasma glucose and insulin concentrations in addition to total and metabolizable energy intake and body weight gain were lower in rats fed the SPI-cornstarch diet than in those fed the casein-sucrose diet. Feeding the SPI-cornstarch diet compared with feeding either the casein-cornstarch or the SPI-sucrose diet also caused lower plasma glucose concentrations and a concomitant trend (p = 0.06) to reduced energy intake and body weight gain. Therefore, the reducing effects of the SPI-cornstarch diet compared with the casein-cornstarch, the casein-sucrose, and the SPI-sucrose diets on body energy and fat gains may result from reductions in energy intake and in plasma glucose concentrations.     

Effects of oral administration of nicotine on organ weight, serum testosterone level and testicular histology in adult male rats

This study investigated the effects of oral administration of nicotine on body and reproductive organ weight, serum testosterone level and testicular histology in adult male rats. Forty male rats divided into five groups and treated for a period of 30 days with 0.5mg/kg (low dose) and 1.0 mg/kg (high dose) body weight of nicotine while the control rats received 0.2 ml/kg normal saline. The fourth and fifth groups were gavaged with 0.5mg/kg and 1.0mg/kg body weight of nicotine but were left untreated for another 30 days. These groups served as the recovery groups.  At the end of each experimental period, the animals were scarified and their reproductive organs were removed and weighed immediately. There was no significant change in the body weight. There was a significant decrease (p <0.05) in the testicular and epididymal weight of rats for both treatments while the decrease in the seminal vesicle weight for both treatment groups was not significant. The prostate weight was not significantly increased in both groups. The recovery groups showed appreciable recovery in their organ weight. Serum level of testosterone of both groups was significantly decreased in a dose dependent manner when compared with those of the control rats. The histological section showed testicular degeneration and disorganization in the cytoarchitecture, as the observed changes were pronounced in the high dose group than the low dose group. However, there were both regeneration of the germinal epithelium and restructuring of the interstitum towards normal in the recovery groups. No lesion was observed in the epididymis of the rats. The results suggest that nicotine has deleterious effect on the male reproductive organ of albino rats ameliorated by nicotine cessation.     

Exogenous human growth hormone reduces body fat in obese women

The effects of biosynthetic methionyl human growth hormone (met-hGH) on body composition and endogenous secretion of insulin-like growth factor I (IGF-I) were studied in obese women ranging between 138 and 226% of ideal body weight. Following double-blind procedures, 12 subjects were assigned at random to either treatment with met-hGH (n = 6, 0.08 mg/kg desirable body weight) or placebo (n = 6, bacteriostatic water diluent). Treatments were delivered intramuscularly three times per week for a period of 27-28 days. Subjects were instructed to follow a weight-maintaining diet and their pre- and posttreatment kilocaloric intake was monitored for verification. The baseline peak serum GH response to L-dopa/arginine stimulation for the study population as a whole, was in the hyposecretory range (9.6 +/- 1.9 ng/ml), accompanied by a low level of circulating IGF-I (0.56 +/- 0.09 U/ml). Hydrodensitometry revealed that the met-hGH-treated subjects had a significant reduction in body fat, while an observed mean increase in fat-free mass (FFM) approached significance. The percent change in body fat was unrelated to pretreatment levels of body fat, total body weight, or initial endogenous GH status. Changes in circulating IGF-I were similar to those for FFM, with increases approaching significance. There were no significant changes in body composition or IGF-I in the placebo-treated subjects. No significant differences were observed in the self-reported dietary intake of kilocalories during the experimental period between the two groups. We conclude that exogenous GH reduces body fat in obese women in the apparent absence of significant kilocaloric restriction. The effect appears to be unrelated to endogenous GH secretion or body composition.     

Compensatory growth in the gibel carp following feed deprivation: temporal patterns in growth, nutrient deposition, feed intake and body composition

To investigate the nature of compenstory growth in fish, an 8 week study at 28°C was performed on juvenile gibel carp Carassius auratus gibelio weighing 6·6 g. Fish were starved for 0 (control), 1 (S1) or 2 (S2) weeks and then re-fed to satiation for 5 weeks. Weekly changes in weight gain, feed intake and body composition were monitored during re-feeding. No significant difference was found in final body weight between the three groups, indicating complete compensation in the deprived fish. The deprived groups caught up in body weight with that of the control after 2 weeks of re-feeding. Body fat: lean body mass ratio was restored to the control level within 1 week of re-feeding. In the re-feeding period, weekly gains in body weight, protein, lipid, ash and energy in the S1 group were significantly higher than in the controls for 1 week. For the S2 group, weekly gains in body weight, lipid, ash and energy were higher than in the controls for 2 weeks, and gain in protein was higher than in the controls for 3 weeks, though gain in body energy became elevated again during the last 2 weeks of the experiment. Feed intake remained higher than the control level for 3 weeks in the S1 group and 4 weeks in the S2 group. Growth efficiency was not significantly different among the three groups in any of the weeks during re-feeding. Compensatory responses in growth and especially feed intake tended to last longer than the recovery of body composition.     

Effect of intense military training on body composition

Individuals in a structural physical training program can show beneficial changes in body composition, such as body fat reduction and muscle mass increase. This study measured body composition changes by using 3 different techniques-skinfold thickness (SF) measurements, air displacement plethysmography (BOD-POD), and dual-energy x-ray absorptiometry (DXA)-during 9 months of intense training in healthy young men engaged in military training. Twenty-seven young men were recruited from a special faction of the Italian Navy. The program previewed three phases: ground combat, sea combat, and amphibious combat. Body composition was estimated at the beginning, in the middle, and at the end of the training. After the subjects performed the ground combat phase, body composition variables significantly decreased: body weight (P < 0.05), fat-free mass (FFM) (P < 0.001), and fat mass (FM) (P < 0.03). During the amphibious combat phase, body weight increased significantly (P < 0.01), mainly because of an increase in FFM (P < 0.001) and a smaller mean decrease in FM. There was a significant difference (P < 0.05) in circumferences and SF at various sites after starting the training course. Bland-Altman analysis did not show any systematic difference between FM and FFM measured with the 3 different techniques on any occasion. On any visit, FFM and FM correlation measured by BOD-POD (P = 0.90) and DXA was significantly greater than measured by SF. A significant difference was found in body mass index (BMI) measured during the study. BOD-POD and SF, compared with DXA, provide valid and reliable measurement of changes in body composition in healthy young men engaged in military training. In conclusion, the findings suggest that for young men of normal weight, changes in body weight alone and in BMI are not a good measure to assess the effectiveness of intense physical training programs, because lean mass gain can masquerade fat weight loss.     

男性吸烟者体重对烟碱引起的生热作用和儿茶酚胺释放的影响

本研究的目的是在中年男子中观察禁食情况下吸烟后烟碱对安静时能量消失（resting energy expenditure,REE)和血浆儿茶酚胺浓度的影响,并且在正常体重（BMI≤25kg/m^2),和超重（BMI＞25kig/m^2)吸烟者之间比较吸烟引起的REE和血浆儿茶酚胺的急性反应是否有差别,对32名禁食的男性吸烟者用间接测热法分别在吸烟前和吸2支含0．16mg烟碱（低烟碱）或2支含1．74mg烟碱（高烟碱）香烟30min后测定REE,同时测定血浆中烟碱和去甲肾上腺素浓度,正常体重组在吸低烟碱烟后和超重组不认在吸低烟碱烟或高烟碱烟后,REE和血浆儿茶酚胺均无明显改变,而在正常体重组中,吸高烟碱烟后血浆去甲肾上腺素浓度升,时REE增加7．2％,如果将血浆烟碱水平作为一个共变量进行分析,则吸烟后血浆去甲肾上腺素浓度和REE的改变也不明显,表明吸烟后的生热效应是因血浆烟碱浓度升高而引起的,体重对烟碱的生热效应能发生影响,在超重的吸烟者中烟碱的生热效应减弱,由此推测,正常体重的吸烟者在戒烟后,由于不再有吸烟引起的耗能生热,可能导致体重增加。     

Effects of eight weeks of caffeine supplementation and endurance training on aerobic fitness and body composition

The purpose of this study was to examine the effects of daily administration of a supplement that contained caffeine in conjunction with 8 weeks of aerobic training on VO(2)peak, time to running exhaustion at 90% VO(2)peak, body weight, and body composition. Thirty-six college students (14 men and 22 women; mean +/- SD, age 22.4 +/- 2.9 years) volunteered for this investigation and were randomized into either a placebo (n = 18) or supplement group (n = 18). The subjects ingested 1 dose (3 pills = 201 mg of caffeine) of the placebo or supplement per day during the study period. In addition, the subjects performed treadmill running for 45 minutes at 75% of the heart rate at VO(2)peak, three times per week for 8 weeks. All subjects were tested pretraining and posttraining for VO(2)peak, time to running exhaustion (TRE) at 90% VO(2)peak, body weight (BW), percentage body fat (%FAT), fat weight (FW), and fat-free weight (FFW). The results indicated that there were equivalent training-induced increases (p < 0.05) in VO(2)peak and TRE for the supplement and placebo groups, but no changes (p > 0.05) in BW, %FAT, FW, or FFW for either group. These findings indicated that chronic use of the caffeine-containing supplement in the present study, in conjunction with aerobic training, provided no ergogenic effects as measured by VO(2)peak and TRE, and the supplement was of no benefit for altering body weight or body composition.     

Anthropometric measures, body composition, body fat distribution, and knee osteoarthritis in women

Objective: Increased BMI is a well‐recognized risk factor for radiographic knee osteoarthritis (rKOA); however, the contributions of the components of body composition, body fat distribution, and height to this association are not clear. Research Methods and Procedures: We examined 779 women ≥45 years of age from the Johnston County Osteoarthritis Project. Body composition was assessed using DXA, and rKOA was defined as Kellgren‐Lawrence grade ≥2. Logistic regression models examined the association between rKOA and the fourth compared with the first quartiles of anthropometric, body composition, and fat distribution measures adjusting for age, ethnicity, and prior knee injury. Results: The adjusted odds ratios and 95% confidence interval of BMI and weight were 5.27 (3.05, 9.13) and 5.28 (3.05, 9.16), respectively. In separate models, higher odds of rKOA were also found for fat mass [4.54 (2.68, 7.69)], percent fat mass [3.84 (2.26, 6.54)], lean mass [3.94 (2.22, 6.97)], and waist circumference [4.15 (2.45, 7.02)]. Waist‐to‐hip ratio was not associated with rKOA [1.45 (0.86, 2.43)], and percent lean mass was associated with lower odds [0.20 (0.11, 0.35)]. Taller women had higher odds of rKOA after adjustment for BMI [1.77 (1.05, 3.00)]. Discussion: This study confirms that BMI and weight are strongly associated with rKOA in women and suggests that precise measurements of body composition and measures of fat distribution may offer no advantage over the more simple measures of BMI or weight in assessment of risk of rKOA.     

The effect of beta-hydroxy beta-methylbutyrate on muscular strength and body composition in collegiate football players

This study assesses the effects of daily beta-hydroxy beta-methylbutyrate (HMB) supplementation on muscular strength (bench press, squats, and power cleans) and body composition (body weight and body fat) among collegiate football players undergoing a strenuous exercise program. Subjects were collegiate football players (n = 35) training under the supervision of certified strength coaches averaging 20 hours of weekly exercise. In the first supplementation period, 16 of the 35 subjects were supplemented with 3 g of HMB per day for 4 weeks; the other 19 received a placebo followed by a 1-week washout period and then a second supplementation period in a randomized double-blind crossover, placebo design. There were no significant changes (p > 0.05) in muscular strength, including bench press, squats, and power cleans, among the subjects. There were also no significant changes (p > 0.05) in body composition, including body fat and body weight. Very little clinical evidence exists for supplementing HMB in athletic populations.     

Quantitative trait loci for chemical body composition traits in pigs and their positional associations with body tissues, growth and feed intake

In this study, quantitative trait loci (QTL) for chemical and physical body composition, growth and feed intake in pigs were identified in a three-generation full-sib population, developed by crossing Pietrain sires with a commercial dam line. Phenotypic data from 315 F₂ animals were available for protein and lipid deposition measured in live animals by the deuterium dilution technique at 30-, 60-, 90-, 120- and 140-kg body weight. At 140-kg body weight, carcass characteristics were measured by the AutoFOM grading system and after dissection. Three hundred and eighty-six animals from 49 families were genotyped for 51 molecular markers covering chromosomes SSC2, SSC4, SSC8, SSC9, SSC10 and SSC14. Novel QTL for protein (lipid) content at 60-kg body weight and protein (lipid) accretion from 120 to 140 kg were detected on SSC9 near several previously detected QTL for lean and fat tissue in neck, shoulder and ham cuts. Another QTL for lipid accretion was found on SSC8, closely associated with a QTL for intramuscular fat content. QTL for daily feed intake were detected on SSC2 and SSC10. The favourable allele of a QTL for food conversion ratio (FCR) on SSC2 was associated with alleles for increased lean tissue and decreased fat tissue. Because no QTL for growth rate were found in the region, the QTL for FCR is most likely due to a change in body composition. These QTL provide insights into the genomic regulation of chemical or physical body composition and its association with feed intake, feed efficiency and growth.     

Effects of short-term dehydroepiandrosterone supplementation on body composition in young athletes

Dehydroepiandrosterone (DHEA) is often promoted as a slimming and weight/fat loss agent and ingestion of DHEA may have hypolipidemic and anti-obesity properties. The main aim of this study was to examine the effects of acute DHEA intake on body composition and serum steroid hormones in young athletes. Twenty young (19 to 22 years) male soccer players were allocated into two randomly assigned trials in double-blind design by ingesting 100-mg daily oral DHEA or as placebo (PLA) for 28 days. Body mass was not affected by 4 weeks of DHEA supplementation (P > 0.05). No significant changes in body mass index (BMI), waist-to-hip ratio (WHR) and body fat or total muscle mass for the two groups were detected at the end of the trial (P > 0.05). There was no within- or between-group difference in arm fat index (AFI) and corrected mid-upper-arm muscle area (cAMA) (P > 0.05). Treatment with DHEA resulted in a significant increase of total testosterone, estradiol and DHEA-S levels in treated subjects versus the placebo group (P < 0.05). Results of this study suggest that DHEA supplementation has no beneficial effects on body composition in young competitive athletes.     

QTLs for pre- and postweaning body weight and body composition in selected mice

In an intercross between the high-body-weight-selected mouse line NMRI8 and the inbred line DBA/2, we analyzed genetic effects on growth during the suckling period and after weaning during the juvenile phase of development. QTL mapping results indicated that a switch of gene activation might occur at the age of three weeks when animals are weaned. We found QTLs for body weight with major effects at the age of two and three weeks when animals are fed by their mothers, and QTLs with highest effects after weaning when animals have to live on their own under ad libitum access to food. Specific epistatic effects on body weight at two and three weeks and epistatic interaction influencing growth after weaning support this finding. QTL effects explained the greatest variance during puberty when animals grow fastest and become fertile. In the present study, all except one QTL effect for early body weight had dominance variance components. These might result from direct single-locus-dominant allelic expression, but also from the identified epistatic interaction between different QTLs that we have found for body weight at all ages. Beside body weight, body composition traits (muscle weight, reproductive fat weight, weight of inner organs) were analyzed. Sex-dimorphic QTLs were found for body weight and fat deposition. The identified early-growth QTLs could be the target of epigenetic modifications which might influence body weight at later ages.     

Stem cell activation in adults can reverse detrimental changes in body composition to reduce fat and increase lean mass in both sexes

Detrimental changes in body composition are often associated with declining levels of testosterone. Here, we evaluated the notion that multipotent mesenchymal stem cells, that give rise to both fat and muscle tissue, can play a significant role to alter existing body composition in the adult. Transgenic mice with targeted androgen receptor (AR) overexpression in stem cells were employed. Wild-type littermate and AR-transgenic male and female mice were gonadectomized and left untreated for 2 months. After the hypogonadal period, mice were then treated with 5α-dihydrotestosterone (DHT) for 6 weeks. After orchidectomy (ORX), wild-type males have reduced lean mass and increased fat mass compared to shams. DHT treatment was beneficial to partially restore body composition. In wild-type females, ovariectomy (OVX) produced a similar change but there was no improvement with DHT. In targeted AR transgenic mice, DHT treatment increased lean and reduced fat mass to sham levels. In contrast to wild-type females, DHT treatment in female transgenic mice significantly ameliorated the increased fat and decreased lean mass changes that result after OVX. Our results show that DHT administration reduces fat mass and increases lean mass in wild-type males but not females, indicating that wild-type females are not as sensitive to androgen treatment. Because both male and female transgenic mice are more responsive than wild-type, results suggest that body composition remains linked to stem cell fate in the adult and that targeted androgen signaling in stem cells can play a significant role to reverse detrimental changes in body composition in both sexes.