Total and resting energy expenditure in obese women reduced to ideal body weight.

Obesity could be due to excess energy intake or decreased energy expenditure (EE). To evaluate this, we studied 18 obese females (148 +/- 8% of ideal body weight [IBW], mean +/- SD) before and after achieving and stabilizing at IBW for at least 2 mo and a control group of 14 never obese females (< 110% of IBW or < 30% fat). In the obese, reduced obese, and never obese groups, the percent of body fat was 41 +/- 4%, 27 +/- 4%, and 25 +/- 3%; total energy expenditure (TEE) was 2704 +/- 449, 2473 +/- 495, and 2259 +/- 192 kcal/24 h; while resting metabolic rate was 1496 +/- 169, 1317 +/- 159, and 1341 +/- 103 kcal/24 h, respectively. 15 obese subjects who withdrew from the study had a mean initial body composition and EE similar to the subjects who were successful in achieving IBW. In 10 subjects followed for at least one year after stabilizing at IBW there was no significant relationship between the deviation from predicted TEE at IBW and weight regain. These studies indicate that, in a genetically heterogeneous female population, neither the propensity to become obese nor to maintain the obese state are due to an inherent metabolic abnormality characterized by a low EE.

The effects of weight reduction to ideal body weight on body fat distribution.

Obesity is a well-known health risk factor. Several studies have demonstrated that upper-body fat distribution plays a major role in the association between increased adiposity and metabolic disorders. The present study was undertaken to evaluate changes in intraabdominal and subcutaneous fat areas in obese subjects undergoing a weight reduction to their ideal body weight (IBW), as defined by a body mass index (BMI) no greater than 21 or body fat less than 30%, and compare the fat distribution at IBW with that of never-obese control subjects. We studied 33 obese women (151% +/- 1% of IBW; BMI, 31.6 +/- 2.5 [mean +/- SE]) before and after weight loss and a control group of 16 never-obese women (101.0% +/- 1.0% of IBW; BMI, 21.2 +/- 1.1). Eighteen obese women successfully achieved and stabilized at IBW for at least 2 months. Nonsuccessful obese subjects were significantly younger than reduced-weight subjects, but other physical characteristics were similar. In obese, reduced-obese, and never-obese groups, weight was 85 +/- 2.0, 62 +/- 1, and 58 +/- 1 kg; percent body fat was 41% +/- 1%, 24% +/- 2%, and 23% +/- 1%; intraabdominal fat area was 82 +/- 5, 28 +/- 3, and 25 +/- 4 cm2; waist subcutaneous fat area was 275 +/- 15, 120 +/- 9, and 81 +/- 7 cm2; hip subcutaneous fat area was 416 +/- 17, 204 +/- 10, and 195 +/- 7 cm2; and waist to hip ratio (WHR) was 0.84 +/- 0.02, 0.77 +/- 0.01, and 0.73 +/- 0.01, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)