Changes in plasma amino acid concentrations in overweight and obese men after weight loss program including dietary modification and aerobic exercise

Obesity causes lifestyle diseases that increase one’s mortality risk. Studies have demonstrated that plasma amino acid concentrations may be useful for screening several lifestyle-related diseases. This study aimed to investigate the effects of weight loss using dietary modification and aerobic exercise training on plasma amino acid concentrations in overweight and obese men. Thirty-two overweight or obese men (age, 49 ± 2 years; body mass index, 29.2 ± 0.3 kg/m2) completed a 12-week intervention consisting of dietary modification (group lectures and individual counseling 8 times over 12 weeks; 1680 kcal/day) and aerobic exercise training (90 min/day, 3 times weekly, 60–80% maximum heart rate). Before and after 12 weeks, body mass index, energy intake, physical activity, and plasma concentrations for 39 kinds of amino acids were measured. The 12-week lifestyle modification led to successful weight loss (-12.6 kg). Total energy intake significantly decreased, while peak oxygen uptake, physical activity and step count significantly increased after the 12-week lifestyle modification. Plasma concentrations for 6 kinds of amino acids were significantly increased, while those for 9 kinds of amino acids were significantly decreased after the 12-week lifestyle modification. Our findings suggest that the lifestyle intervention consisting of dietary modification and aerobic exercise training significantly changes plasma concentrations of several kinds of amino acids in overweight and obese men.