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Background: Although physical inactivity is believed to contribute to the rising prevalence of obesity, the role and magnitude of its contribution to weight gain are unknown., Objective: We compared total free-living activity energy expenditure (AEE) and physical activity level in women successful and unsuccessful at maintaining a normal body weight., Design: Premenopausal, generally sedentary women were studied at their normal weight and 1 y later after no intervention. Two groups were identified on the basis of extreme weight changes: maintainers (n = 27) had a weight gain of less-than-or-equal 3% of their initial body weight ( less-than-or-equal 2 kg/y) and gainers (n = 20) had a weight gain of >10% (>6 kg/y). At baseline and follow-up, evaluations were conducted during 4 wk of diet-controlled, energy-balance conditions. Free-living AEE and physical activity were assessed with the use of doubly labeled water, exercise energy economy and muscle strength with the use of standardized exercise tests, and sleeping EE and substrate utilization with the use of chamber calorimetry., Results: Maintainers lost a mean (plus minusSD) of 0.5 plus minus 2.2 kg/y and gainers gained 9.5 plus minus 2.1 kg/y. Gainers had a lower AEE (P < 0.02), a lower physical activity level (P < 0.01), and less muscle strength (P < 0.001); these differences between groups remained significant from baseline to follow-up. Sleeping EE, exercise economy, and sleeping or 24-h substrate utilization were not significantly different between the 2 groups. A lower AEE in the gainers explained approximately 77% of their greater weight gain after 1 y., Conclusion: The general US population should increase their daily physical activity levels to decrease the rising prevalence of obesity.

Background: Obese persons generally regain lost weight, suggesting that adaptive metabolic changes favor return to a preset weight. Objective: Our objective was to determine whether adaptive changes in resting metabolic rate (RMR) and thyroid hormones occur in weight-reduced persons, predisposing them to long-term weight gain. Design: Twenty-four overweight, postmenopausal women were studied at a clinical research center in four 10-d study phases: the overweight state (phase 1, energy balance; phase 2, 3350 kJ/d) and after reduction to a normal-weight state (phase 3, 3350 kJ/d; phase 4, energy balance). Weight-reduced women were matched with 24 never-overweight control subjects. After each study phase, assessments included RMR (by indirect calorimetry), body composition (by hydrostatic weighing), serum triiodothyronine (T3), and reverse T3 (rT3). Body weight was measured 4 y later, without intervention. Results: Body composition-adjusted RMR and T3:rT3 fell during acute (phase 2) and chronic (phase 3) energy restriction (P < 0.01), but returned to baseline in the normal-weight, energy-balanced state (phase 4; mean weight loss: 12.9 ± 2.0 kg). RMR among weight-reduced women (4771 ± 414 kJ/d) was not significantly different from that in control subjects (4955 ± 414 kJ/d; P = 0.14), and lower RMR did not predict greater 4-y weight regain (r = 0.27, NS). Conclusions: Energy restriction produces a transient hypothyroid-hypometabolic state that normalizes on return to energy-balanced conditions. Failure to establish energy balance after weight loss gives the misleading impression that weight-reduced persons are energy conservative and predisposed to weight regain. Our findings do not provide evidence in support of adaptive metabolic changes as an explanation for the tendency of weight-reduced persons to regain weight. [ABSTRACT FROM AUTHOR]

This article presents a case report of an individual who developed a pattern of self-induced vomiting subsequent to gastroplasty surgery for morbid obesity. A description of the history, symptomatology, and disordered eating pattern is provided along with the clinical outcome from a cognitive-behavioral intervention. The results are discussed with regard to the need for future evaluation of eating behavior patterns in postgastroplasty patients. It was concluded that the syndrome is similar in many respects to the bulimic pattern observed in normal weight females. [ABSTRACT FROM AUTHOR]

The ratio of resting metabolic rate (RMR) to fat-free mass (FFM) is often used to compare individuals of different body sizes. Because RMR has not been well described over the full range of FFM, a literature review was conducted among groups with a wide range of FFM. It included 31 data sets comprising a total of 1111 subjects: 118 infants and pre-schoolers, 323 adolescents, and 670 adults; FFM ranged from 2.8 to 106 kg. The relationship of RMR to FFM was found to be nonlinear and average slopes of the regression equations of the three groups differed significantly (P < 0.0001). For only the youngest group did the intercept approach zero. The lower slopes of RMR on FFM, at higher measures of FFM, corresponded to relatively greater proportions of less metabolically active muscle mass and to lesser proportions of more metabolically active nonmuscle organ mass. Because the contribution of FFM to RMR is not constant, an arithmetic error is introduced when the ratio of RMR to FFM is used. Hence, alternative methods should be used to compare individuals with markedly different FFM. [ABSTRACT FROM AUTHOR]

Two studies were performed to investigate the association between body fat mass and fat oxidation. The first, a cross-sectional study of 106 obese women maintaining stable body weight, showed that these two variables were significantly correlated (r = 0.56, P < 0.001) and the regression coefficient indicated that a 10-kg change in fat mass corresponded to a change in fat oxidation of ~20 g/d. The second, a prospective study, validated this estimate and quantifies the long-term adaptations in fat oxidation resulting from body fat loss. Twenty-four moderately obese women were studied under controlled dietary conditions at stable weight before and after mean weight and fat losses of 12.7 and 9.8 kg, respectively. The reduction in fat oxidation was identical to that predicted by the above regression. We conclude that changes in fat mass significantly affect fat oxidation and that this process may contribute to the long-term regulation of fat and energy balance in obese individuals. [ABSTRACT FROM AUTHOR]

Presents a study which examined the effects of high and low carbohydrate diet on patients with diabetes mellitus. Goals of diet therapy; Comparison of the effects of diet on diabetic control, insulin secretion and blood lipids of the patients; Assessment of the concept of carbohydrate-induced hypertriglyceridemia.