EFFECT OF LARGE EXERCISE-INDUCED WEIGHT LOSS ON BODY COMPOSITION AND FAT DISTRIBUTION IN OBESE MALES

Abstract

This study examined the effects of large exercise-induced weight loss on body composition and fat distribution in obese Singaporean males. 30 obese males (mean age 19.8 ± 0.6 yrs) were evaluated before (pre-training) and after (post-training) four months of regimented training in the Singapore Armed Forces. 30 obese (mean age 19.2 ± 1.3yrs) males without training were monitored as control subjects. Fat free mass (FFM), fat mass (FM) and per cent (%) body fat were determined from skinfold measurements. Body mass index (BMI) and waist hip ratio (WHR) were calculated from height, weight and circumference measures taken pre- and post-training using standard methods. Differences between pre- and post-training responses were analyzed with a paired t-test. Results are presented in the table below (values are Mean ± SD; ***P < 0.001) TABLE Subjects lost 12.0 ± 3.6 kg (P < 0.001) from pre- to post-training, which was attributable to a reduction in FM (P < 0.001), as FFM was unchanged. Significant changes were observed in the measures of body fat distribution. Both waist circumference and hip circumference decreased (P < 0.01), the reduction in waist circumference (13.7%) being greater than the reduction in hip circumference (7.7%) as reflected by the decrease in WHR (P < 0.001). These data reveal that large exercise induced weight losses are associated with a maintenance of FFM, unlike diet induced weight losses of the same magnitude. In addition, the significant reduction in WHR observed after training indicates a greater mobilization of upper body fat and a preferential loss of fat from this region. Thus, exercise-induced weight loss is associated with a reduction in abdominal obesity and a corresponding maintenance of FFM. Such effects on body composition should reduce disease risk and the eventual weight regain that typically follows diet-induced weight losses with obese subjects.Table