A 3-day high-fat/low-carbohydrate diet does not alter exercise-induced growth hormone response in healthy males

Objective: The purpose of the present study was to examine the effects of 3 days isoenergetic high-fat/low-carbohydrate diet (HF-LC) relative to low-fat/high-carbohydrate diet (LF-HC) on the exercise-induced growth hormone (GH) response in healthy male subjects. Design: Ten healthy young males participated in this study. Each subject consumed the HF-LC (18 +/- 1% protein, 61 +/- 2% fat, 21 +/- 1% carbohydrate, 2720 kcal per day) for 3 consecutive days after consuming the LF-HC (18 +/- 1% protein, 20 +/- 1% fat, 62 +/- 1% carbohydrate, 2755 kcal per day) for 3 consecutive days. After each dietary intervention,period, the hormonal and metabolic responses to an acute exercise (30 min of continuous pedaling at 60% of V over dot O-2max) were compared. The intramyocellular lipid (IMCL) contents in the vastus lateralis, soleus, and tibialis anterior were evaluated by proton magnetic resonance spectroscopy. Results: Serum GH concentrations increased significantly during the exercise after both the HF-LC and LF-HC periods (P < 0.05). However, the exercise-induced GH response was not significantly different between the two periods. Fat utilization and lipolytic responses during the exercise were enhanced significantly after the HF-LC period compared with the LF-HC period. IMCL content did not differ significantly in any portion of muscle after the dietary interventions. Conclusions: We could not show that short-term HF-LC consumption changed significantly exercise-induced GH response or IMCL content in healthy young males. (C), 2015 Elsevier Ltd. All rights reserved.