Effects of aerobic exercise, fat oxidation, and diet limitation on target fat mass reduction and appetite-regulating hormone levels

This study aims to investigate changes in plasma lipid concentrations and appetite-regulating hormone levels after a 4% body fat reduction using a 9-week intervention involving aerobic exercise, a fat-oxidizing agent, and diet limitation. After the 9-week intervention, the aerobic exercise plus hydroxycitric acid (EX+HCA), exercise (EX), and diet limitation (DIET) groups achieved the target 4% body fat reduction from the baseline value. None of the plasma lipid indicators showed significant intergroup differences, indicating that plasma lipid levels are not influenced by body weight regulation. With regard to appetite-regulating hormones, no significant intergroup differences were observed in glucose, insulin, or glucagon-like peptide-1 levels, unlike ghrelin and leptin. Ghrelin levels in particular tended to decrease in the DIET group and increase in the HCA+EX and EX groups. Leptin levels significantly decreased in the HCA+EX and EX groups, whereas no differences were observed in the DIET group. Such results indicate that exercise alone without the administration of obesity diet supplements induces elevation in ghrelin levels and reduction in leptin levels, but that diet restriction alone does not influence changes in leptin levels. Taken together, we could not confirm any synergic effects arising from the use of a fat-oxidizing agent during an exercise program to control body weight. Furthermore, diet limitation unsupported by exercise had no effect on muscle mass reduction or appetite-regulating hormone levels; thus, it is not recommended as an effective body weight control method.