SERUM LEPTIN CONCENTRATIONS AND WEIGHT-GAIN IN POSTOBESE, POSTMENOPAUSAL WOMEN

Objective: This study was designed to determine if serum leptin concen trations (adjusted for fat mass) after weight loss on a low-calorie di et predict subsequent weight gain, Research Methods and Procedures: Bo dy composition and serum leptin concentrations were determined on 14 m oderately obese, postmenopausal, nondiabetic women with a familial pre disposition to obesity. Assessments were obtained under tightly contro lled metabolic ward conditions of macronutrient intake and weight main tenance both before (obese state) and after a mean weight loss of 12.0 kg to normal body weight (postobese state).:Four years later, without intervention, body weight and body composition were reassessed. Resul ts: Weight loss resulted in significant decreases in fat mass (29.7 +/ - 5.4 vs. 20.3 +/- 4.7; kg), body mass index (27.7 +/- 1.6 vs. 23.0 +/ - 1.5; kg/m(2)), percent body fat (40.7 +/- 4.3 vs. 33.1 +/- 5.0), and serum leptin concentrations (31.8 +/- 16.0 vs. 11.5 +/- 5.4; ng/mL). Serum leptin concentrations a ere positively correlated (p<0.05) with fat mass in both the obese and postobese states (r = 0.67 and r = 0.56 , respectively). However, residual serum leptin concentrations (adjust ed for fat mass) in the obese and postobese states were not related to changes in body weight (p = 0.61 and 0.52), fat mass (p = 0.72 and 0. 42), body mass index (p = 0.59 and 0.33), or percent body fat (p = 0.8 4 and 0.46) over the follow-up period. Discussion: These finding do no t support the hypothesis that relatively low concentrations of leptin predict weight regain after weight loss. However, because the number o f subjects in this study was limited, further studies are warranted.