Orexin-A and Glucose Serum in Inactive Overweight Men: Investigation the Effect of Acute Aerobic Exercise Training Following Four Different Diets

It is specified that serum levels of Orexin-A has a negative correlation with serum levels of glucose. Exercise and diet are the main regulators of blood circulation of Orexin-A. Therefore, the aim of current study was to investigate the effect of acute aerobic exercise following four different diets on the levels of Orexin-A and glucose in overweight men.

In this quasi-experimental single-blinded crossover study, 10 overweight men (aged 23± 6.1 and BMI 29.26 ± 0.47), attended the physiology lab for 4 sessions with a week interval. In each session, two hours after having Normal (N), High carbohydrate (HCHO), High protein (HP) and High-fat (HF) diets, subjects performed 30 min treadmill aerobic exercise with 60-70% of maximum heart rate. In each session, three blood samples were taken in fasting, 2 hours after the diet (before exercise) and after the exercise.

Serum levels of Orexin-A after acute aerobic exercise following HCHO and HP diet were significantly higher compared to HF diet (P≤ 0.019 and P≤ 0.033, respectively). There was no significant difference in serum levels of glucose after aerobic exercise following 4 different diets (P = 0.072).

The present study demonstrated that in overweight men, calorie intake especially from HF diet, reduces serum levels of Orexin-A. In addition, acute aerobic exercise after having HF diet did not change serum levels of Orexin-A. Also, there was no significant difference in glucose levels as a result of comparing 4 sessions.