Effect of a high-fat meal on the growth hormone response to exercise in children

Exercise-induced growth hormone (GH) secretion may significantly modulate growth and development in children. Altered physiological GH responses, therefore, may reduce the beneficial effects of exercise. High-fat food ingestion before exercise blunts the GH response in adults, but it is unknown whether this occurs in children. We therefore performed standard exercise tests, following a high-fat meal or placebo, in 12 children, age 11-15 (6 M, 6 F). GH, insulin-like growth factor-I, glucose, insulin, glucagon, cortisol, epinephrine and interleukin-6 samples were drawn at baseline, end-exercise, and 30 and 60 min post-exercise. While GH was similar at baseline in all experiments, the exercise-induced GH peak was lower after the high-fat meal (6.7 ± 1.6 ng/l vs 11.8 ± 2.4 ng/l, p <0.02). Other exercise responses were not affected by prior fat ingestion. A high-fat meal before exercise, therefore (a common event in Western societies), may reduce the growth factor response to exercise in children, with potential implications for growth and development.