Effects of a 3-week integrated body weight reduction program on leptin levels and body composition in severe obese subjects

The effects of short-term (3 weeks) integrated body weight reduction (BWR) program (including energy-restricted diet, aerobic and strength exercise (5 days/week), nutritional education and psychological counseling) on plasma leptin levels and body composition were investigated in 54 morbidly obese patients (38 females/ 16 males; mean BMI±SE: 41.8±0.1 kg/m2, range 35–58 kg/m2; mean age: 29.8±1.0 yr, age range: 18–46 yr). The BWR program induced a significant (p<0.001) weight loss (BMI reduction: −4.8%) and a significant modification in body composition, consisting in a fat mass (FM) decrease (−7.0±0.4%, p<0.001) with a concomitant fat-free (FFM) mass increase (1.8±0.3%, p<0.001). On average, plasma leptin levels decreased significantly both in males (from 19.4±2.6 ng/ml to 11.6±1.3 ng/ml, p<0.001) and in females (from 41.1±3.6 ng/ml to 29.9±3.0 ng/ml, p<0.001). Both before and after weight loss, leptin levels were positively correlated (p<0.001) with BMI and percent fat mass (FM) values. Weight changes after the BWR program were negatively correlated with baseline leptin concentrations both in absolute terms and expressed per unit FM. In conclusion, a short-term diet plus aerobic/strength training effectively induces body composition changes and reduces plasma leptin levels. Body FM reduction appears to be not the unique determinant of leptin levels regulation and the degree of leptin over-expression may negatively affect weight loss in morbidly obese patients.