Baseline Fat Mass Research Articles

Successful Long‐term Weight Maintenance: A 2‐year Follow‐up

To find factors associated with successful weight maintenance (WM) in overweight and obese subjects after a very low-calorie diet (VLCD). Subjects (133) followed a VLCD (2.1 MJ/d) for 6 weeks in a free-living situation. Of these, 103 subjects (age, 49.6 +/- 9.7 years; BMI, 30.9 +/- 3.8 kg/m(2)) completed the following 2-year WM period. Body weight (BW), body composition, leptin concentration, attitude toward eating, and physical activity were determined right before (t0) and after (t1) the VLCD, after 3 months (t2), after 1 year (t3), after 1.5 years (t4), and after 2 years (t5). BW loss during VLCD was 7.2 +/- 3.1 kg. After 2 years, follow-up BW regain was 69.0 +/- 98.4%. After 2 years of WM, 13 subjects were successful (<10% BW regain), and 90 were unsuccessful (>10% BW regain). At baseline, these groups were significantly different in BMI (33.7 +/- 4.7 vs. 30.5 +/- 3.5 kg/m(2), respectively; p < 0.05) and fat mass (38.3 +/- 9.8 vs. 32.1 +/- 8.3 kg, p < 0.05). Successful subjects increased their dietary restraint significantly more during the whole study period (dietary restraint score, -4.9 +/- 4.4 vs. -2.1 +/- 3.8). Furthermore, %BW regain was associated with the amount of percentage body fat lost during VLCD, which indicates that the more fat lost, the better the WM, suggesting a fat free mass-sparing effect. Characteristics such as the ability to increase dietary restraint and maintain this high level of restraint, fat free mass sparing, and a relatively high baseline BMI and fat mass were associated with successful long-term WM (<10% regain after 2 years).

High plasma leptin predicts an increase in subcutaneous adiposity in children and adults

To investigate the hypothesis that plasma leptin may predict adiposity changes. A population-based cohort study. Fleurbaix and Laventie, in the north of France. In all, 1175 subjects participated, of whom 946 completed measurements at baseline (1999) and follow-up (2001). After excluding 64 subjects obese at baseline, 882 subjects (478 adults, 404 children 8 years and over) were included in the analysis. We measured plasma leptin concentrations at baseline and various adiposity parameters at baseline and follow-up. Partial correlation coefficients (r(p)) between baseline plasma leptin and each adiposity indicator at follow-up were calculated with adjustment for baseline age, pubertal stage, adiposity and familial correlations between siblings. Changes in body mass index and percentage body fat were not related to baseline plasma leptin. High baseline plasma leptin predicted an increase (r(p) (P-value)) in the sum of the four skinfolds (0.18 (<0.0001)), the waist circumference (0.16 (0.0003)) and the waist-to-hip ratio (0.29 (<0.0001)) in adults only, and in the hip circumference in adults (0.20 (<0.0001)) and children (0.22 (<0.0001)). After adjustment for a set of four adiposity variables at baseline (percentage body fat, skinfolds, waist and hip circumferences), baseline plasma leptin predicted only changes in the sum of the four skinfolds in adults (0.15 (0.001)), with similar tendency although not significant in children (0.08 (0.13)). A high leptin relative to baseline fat mass predicts fat mass gain over time, mainly in the subcutaneous location.

Deterioration of insulin sensitivity and beta-cell function in overweight Hispanic children during pubertal transition: A longitudinal assessment

To examine 1-year changes in insulin dynamics in overweight Hispanic children at high-risk of type 2 diabetes as a function of body composition and pubertal transition. Longitudinal changes in insulin dynamics, body composition and maturation were determined in 132 Hispanic children (70 boys/62 girls; aged 10.9 +/- 1.8 years). Body composition was determined by dual energy x-ray absorptiometry and Tanner stage by physical examination. Insulin sensitivity (SI), the acute insulin response to glucose (AIR) and the disposition index (DI; an index of beta-cell function) were determined using an insulin modified intravenous glucose tolerance test. These measures were conducted at baseline and 1-year later. Fat mass increased by 13% (3.0 kg) and SI declined by 24%. In repeated measures analysis of variance, the fall in insulin sensitivity over 1 year remained highly significant even after adjusting for baseline fat mass, age, gender and change in fat mass. The fall in SI was not significantly influenced by Tanner stage. However, subjects in earlier maturation showed a compensatory increase in AIR (i.e. appropriate beta-cell compensation), whereas subjects in the latter stages of maturation did not (i.e. poor compensation). These results indicate that failure to increase AIR in response to the fall in SI may be one factor in the pathogenesis of the progression of pediatric type 2 diabetes in this at risk population.

Predictors of Long‐term Weight Maintenance

The purpose of this study was to evaluate available variables of a long-term weight maintenance study to investigate possible factors predisposing to weight regain after a period of weight loss. The Maastricht Weight Maintenance Study is an ongoing longitudinal study of healthy men and women (29 men and 62 women; 18 to 65 years of age; BMI = 30.2 +/- 3.1 kg/m(2)). A variety of parameters were measured before and after a very-low-energy diet and after a follow-up of at least 2 years. Mean weight loss was 7.9 +/- 3.6 kg, and percent weight regain was 113.8 +/- 98.1%. Percent BMI regain was negatively associated with an increase in dietary restraint (r = -0.47, p < 0.05). Percent weight regain was negatively correlated with baseline resting metabolic rate (r = -0.38, p = 0.01) and baseline fat mass (r = -0.24, p = 0.05) and positively correlated with the magnitude of change in body weight (BW) expressed as maximum amplitude of BW (r = 0.21, p < 0.05). In addition, amplitude of BW was positively correlated with the frequency of dieting (r = 0.57, p < 0.01). The best predictors for weight maintenance after weight loss were an increase in dietary restraint during weight loss, a high baseline resting metabolic rate, a relatively high baseline fat mass favoring a fat-free mass-sparing effect during weight loss, a rather stable BW, and a low frequency of dieting. Therefore, BW maintenance after BW loss seems to be a multifactorial issue, including mechanisms that regulate an individuals' energy expenditure, body composition, and eating behavior in such a way that energy homeostasis is maintained.

Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery

Little is known about the determinants of individual variability in body weight and fat loss after gastric bypass surgery or about the effects of massive weight loss induced by this surgery on energy requirements. The objectives were to determine changes in energy expenditure and body composition with weight loss induced by gastric bypass surgery and to identify presurgery predictors of weight loss. Thirty extremely obese women and men with a mean (+/- SD) age of 39.0 +/- 9.6 y and a body mass index (BMI; in kg/m(2)) of 50.1 +/- 9.3 were tested longitudinally under weight-stable conditions before surgery and after weight loss and stabilization (14 +/- 2 mo). Total energy expenditure (TEE), resting energy expenditure (REE), body composition, and fasting leptin were measured. Subjects lost 53.2 +/- 22.2 kg body weight and had significant decreases in REE (-2.4 +/- 1.0 MJ/d; P < 0.001) and TEE (-3.6 +/- 2.5 MJ/d; P < 0.001). Changes in REE were predicted by changes in fat-free mass and fat mass. The average physical activity level (TEE/REE) was 1.61 at both baseline and follow-up (P = 0.98). Weight loss was predicted by baseline fat mass and BMI but not by any energy expenditure variable or leptin. Measured REE at follow-up was not significantly different from predicted REE. TEE and REE decreased by 25% on average after massive weight loss induced by gastric bypass surgery. REE changes were predicted by loss of body tissue; thus, there was no significant long-term change in energy efficiency that would independently promote weight regain.

Uncoupling protein 3 gene is associated with body composition changes with training in HERITAGE study

The uncoupling protein 3 (UCP3) is a mitochondrial membrane transporter mainly expressed in skeletal muscle that we have shown to be associated with obesity. We have analyzed UCP3 polymorphisms, Val102Ile, Tyr210Tyr, and a new microsatellite GAIVS6 located in the sixth intron, among 276 black and 503 white subjects from the HERITAGE Family Study. Linkage and association studies were undertaken with body composition variables measured in a sedentary state (baseline) and after 20 wk of endurance training (changes). Allele and genotype frequencies were found to be significantly different between whites and blacks. Suggestive linkages (0.009 < or = P < or = 0.033) with Tyr210Tyr were found in blacks and whites for baseline body mass index, fat mass, or leptin level and with GAIVS6 in whites for changes in fat mass and percent body fat. Associations were also found in whites between GAIVS6 and changes in the sum of eight skinfold thicknesses (P = 0.0006), with a borderline result for body mass index (P = 0.06). We concluded that UCP3 could be involved in body composition changes after regular exercise.

CHANGES IN BODY COMPOSITION AFTER 1 YEAR OF RESISTANCE AND WEIGHT-BEARING EXERCISE IN PREVIOUSLY SEDENTARY POST-MENOPAUSAL WOMEN

Two-hundred and forty-one sedentary post-menopausal women (age, 55.2 ± 4.8 y, body fat (%BF), 38.4 ± 6.7%) were randomly assigned to a control (n = 116) or an exercise group (n = 125). Exercisers performed supervised high-intensity resistance exercises (75–85% 1RM) 3 times a week for one year. Whole-body and regional lean soft tissue mass (LST), fat mass (FM), and %BF changes were measured twice (at baseline and 12 months) by DXA. In the training group, mean compliance to training sessions was 77.0% and subjects increased their strength by 41.8% ± 17.9% (average of 1RM tests in 6 core strength exercises). Exercisers had significant increases in whole-body LST (2.2%, p < 0.001), and leg, arm, and trunk lean masses (1.9%, 3.3%, and 2.5% respectively, p < 0.001). Changes in whole-body (−1.6%) and leg FM (−3.3%) in the training group were significantly different (p < 0.05) from changes in the control group (+0.8% and −1.0%, respectively). Weight did not change in any group (p > 0.05) while %BF regression analysis, group assignment was the only significant predictor of changes in body composition, in a model including age, baseline body composition, hormone-replacement therapy (HRT) status, and year past menopause. In the training group, total weight lifted (TWL) during 1 year of strength training significantly correlated with changed in LST (r = 0.36, p < 0.001), after controlling for age and baseline LST. A linear does-response relationship between the two variables described the relationship the best. For changes in FM relationship between TWL and FM change after adjusting for baseline FM and age was not significant (p > 0.05). We conclude that one year of resistance training has significant and positive effects on the LST and body composition of post-menopausal women, independent of weight loss, HRT, and number of year after menopause. The magnitude of weight lifted after one year reflects linearly on increases in lean tissue, as measured by DXA. Supported by NIH AR 39559 and Mission Pharmacal

Association between beta 3-adrenergic receptor polymorphism and a lower reduction in the ratio of visceral fat to subcutaneous fat area during weight loss in Japanese obese women

We investigated whether amino acid substitution of tryptophan by arginine at the residue 64 (64 Arg) of beta 3-adrenergic receptor affects on the degree of reduction in the abdominal fat distribution during a 3-month weight reduction program in either pre- or postmenopausal Japanese women. Beta 3-adrenergic receptor gene polymorphism was examined in 90 Japanese obese women by restriction-enzyme cleavage conformation. The visceral and subcutaneous fat area was measured by magnetic resonance imaging. The baseline body mass index, body weight, fat mass and abdominal subcutaneous and total fat area in 15 obese postmenopausal women with a beta 3-adrenergic receptor (64 Arg) were significantly higher than those in 25 postmenopausal obese women with a beta 3-adrenergic receptor (64 Trp/64 Trp). In contrast, no such differences were found in the 50 premenopausal obese women. After a 3-month weight reduction period, the ratio of visceral to subcutaneous fat areas tended to be lower in both pre-and post-menopausal women with a beta 3-adrenergic receptor (64 Arg), but statistically significant in only the premenopausal obese women (p<0.05). The absolute changes in visceral fat areas in 5 homozygotes with a beta 3-adrenegic receptor (64 Arg/64 Arg) was significantly smaller than those in 50 obese women with a beta 3-adrenegic receptor (64 Trp/64 Trp). These results thus suggest that an amino acid substitution at residue 64 of beta 3-adrenergic receptor may play an important role in the regulation of fat distribution in Japanese obese women.

Determinants of the rate of bone loss in normal postmenopausal women.

Despite a large number of studies assessing relationships between putative risk factors and bone density, it is not known which factors influence the rate of axial bone loss in normal postmenopausal women. We have examined the relationships between the rate of bone loss (delta BMD) and variables related to calcium metabolism, lifestyle, diet (calcium, sodium, caffeine, and protein), body composition, muscle strength, sex hormones, and spinal osteophytosis in 122 normal postmenopausal women participating in a 2-yr prospective randomized placebo-controlled trial of calcium supplementation. Univariate correlation coefficients indicated that delta BMD at most sites was inversely related to baseline BMD and positively related to rate of change in body weight (0.10 < r < 0.36) and fat mass (0.11 < r < 0.42) during the study. Lean mass and its rate of change showed no consistent relationship to delta BMD. There was no correlation between delta BMD and any of the lifestyle, muscle strength, dietary, or hormonal indices or with the severity of spinal osteophytosis. Multiple regression analysis indicated that delta BMD in the total body was directly related to fat mass (P < 0.0001), the rate of change in fat mass (P < 0.0001), the renal tubular reabsorption of calcium (P < 0.01), and calcium treatment (P < 0.01) and inversely to the initial BMD (P < 0.0001; r2 = 0.42; P < 0.0001). Similar effects were seen throughout the skeleton, although the fraction of the variance accounted for was less in the subregions, consistent with the lower precision of measurement of regional bone density. It is concluded that baseline bone density, fat mass, and renal calcium handling are important factors influencing bone loss in normal postmenopausal women.