Effects of resistance exercise and diet on body composition and health in overweight and obese people

The aim of this study was to compare the effects of diet and combination of diet and resistance exercise programmes on body composition and blood parameters in overweight and obese people retrospectively. The follow up files of 260 women and men aged 18-65 years attending a private sports studio were scanned according to the inclusion criteria of the study. Data of overweight and obese individuals with a body mass index of ≥25 kg/m2, free of health problems, who had been through on a diet program (n=47, 22 females, 25 males) and those who performed moderate intensity resistance exercise 2 or 3 days a week in addition to the diet program (n=55, 28 females, 27 males) for 12 weeks were included. Mann-Whitney U test was used for comparisons between groups and Wilcoxon test was used for within groups comparisons. In both sexes, 3-month diet and diet + exercise programmes resulted in significant decreases in all body composition variables including lean body weight, glucose metabolism indicators, all lipid profile indicators except HDL and liver enzymes (p<0.05). In females, body weight, body mass index and lean body mass decreased more in diet + exercise group compared to those in diet group (p<0.05). In males, the effects of diet and diet + exercise programmes on body composition variables were similar (p>0.05). Both diet and diet + exercise programmes reduced fasting blood glucose, HbA1c and HOMA-IR values in both men and women (p<0.05), but the magnitude of the effects were similar (p>0.05). Both programs decreased total cholesterol, triglyceride and LDL levels in men and women (p<0.05), however, the amount of changes were similar (p>0.05), indicating that resistance exercise had no additional contribution over the diet programme on the decrease in TG, LDL and total cholesterol levels. HDL cholesterol levels; increased in the diet + exercise group (p<0.00), while decreased in the diet group, which was statistically significant for women (p<0.05), but not for men (p>0.05). Both three-month diet and diet + exercise programmes led to a decrease in all liver function indicators (p<0.05). The magnitude of the changes was similar for diet and diet + exercise groups, indicating that exercise in addition to diet did not cause any extra changes on AST, ALT and GGT over the diet only programme (p>0.05). In conclusion; diet has a positive effect on body composition and overall health in overweight and obese individuals and moderate resistance exercise in addition to diet has no additional effect.