Effect of Low Calorie Diet and Exercise on Thyroid Hormones and Leptin Levels

Aim of the Work: To investigate the effect of low calorie diet alone and the effect of low calorie diet and exercise on the levels of thyroid hormones, leptin, and BMI. Also we tried to investigate if there is a relation between thyroid hormones and leptin levels. Subjects and Methods: Two groups of normal male subjects, each group consists of 25 person matched for age and BMI. Group I had low calorie diet program for one month (1200-1500 Kcal). Group II had the same low calorie diet in addition to program of therapeutic exercise on treadmill with moderate intensity every other day for one month. Evaluation of free T3, freeT4, TSH, leptin levels, and BMI were done before and after the study. Correlation between thyroid hormones and leptin levels were done. Results: This study showed significant increase in Free T3, T4, and significant decrease in TSH, leptin and BMI after one month of low calorie diet program (group I) compared to their levels before the study. After one month of low calorie diet and the exercise program (group II), a highly significant increase in free T3, T4 and highly significant decrease in TSH, leptin and BMI compared to their levels before the study. Comparing the studied parameters of both groups after the study showed that there is a more significant increase in T3 & T4 and a more significant decrease in TSH & BMI in group II compared to group I. Leptin level showed no statistically significant difference. A positive correlation between BMI and leptin was found in both groups. We found no relation between thyroid hormones and leptin levels. Conclusion: Low calorie diet caused increase in the level of circulating thyroid hormones, and a decrease in TSH, leptin levels and BMI. Low calorie diet and moderate intensity therapeutic exercise caused more significant increase in the level of circulating thyroid hormones, more significant decrease in TSH level and BMI. No statistically significant difference in leptin level of both groups after the study. We found no relation between leptin level and thyroid hormone levels.