THE EFFECTS OF WEIGHT-REDUCTION TO IDEAL BODY-WEIGHT ON BODY-FAT DISTRIBUTION

Obesity is a well-known health risk factor. Several studies have demon strated that upper-body fat distribution plays a major role in the ass ociation between increased adiposity and metabolic disorders. The pres ent study was undertaken to evaluate changes in intraabdominal and sub cutaneous 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 dist ribution 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]) b efore and after weight loss and a control group of 16 never-obese wome n (101.0% +/- 1.0% of IBW: BMI, 21.2 +/- 1.1). Eighteen obese women su ccessfully achieved and stabilized at IBW for at least 2 months. Nonsu ccessful 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 cm(2); waist subcutaneous fat area was 275 +/- 15, 120 +/- 9, and 81 +/- 7 cm(2); hip subcutaneous fat area was 416 +/- 17, 204 +/- 10, and 195 + 7 cm(2); and waist to hip ratio (WHR) was 0.84 +/- 0.02, 0.77 /- 0.01, and 0.73 +/- 0.01, respectively. Our findings indicate that w ith weight reduction to IBW, intraabdominal and hip subcutaneous fat a reas are the same as in individuals who are at IBW, BMI 21.1. and have never been obese. WHR and waist subcutaneous fat area remain signific antly increased as compared with those in never-obese controls (P <.05 ). Copyright (C) 1995 by W.B. Saunders Company