No short-term exercise data exist testing whether training intensity modifies hormonal and perceived appetite in obese adults with prediabetes. Therefore, we compared the effects of short-term moderate-continuous (CONT) vs. high-intensity interval (INT) training on appetite regulation. Twenty-eight obese adults [age: 61.3 ± 1.5 yr; body mass index (BMI): 33.2 ± 1.1 kg/m2] with prediabetes were randomized to work-matched CONT ( n = 14) or INT ( n = 14) training for 2 wk. Plasma acylated ghrelin (AG), des-acylated ghrelin (dAG), active glucagon-like peptide-1 (GLP-1), and insulin were measured at 0, 30, and 60 min of a 75-g oral glucose tolerance test (OGTT) before and after training. Visual analog scales were administered at 0 and 120 min during the OGTT to examine perceived appetite. Three-day food logs were collected before and after testing to assess ad libitum diet. CONT and INT increased peak oxygen consumption ( P < 0.01) and decreased BMI ( P < 0.01). Although neither intervention altered fasting levels of AG ( P = 0.94), dAG ( P = 0.36), or insulin ( P = 0.67), CONT raised GLP-1 compared with INT ( P = 0.05). Exercise training did not affect postprandial suppression of AG ( P = 0.81) and dAG ( P = 0.67) or stimulation of GLP-1 ( P = 0.67) and insulin ( P = 0.32). Both interventions tended to decrease total energy and protein intake ( P = 0.09 and P = 0.05, respectively), despite no change in fasting hunger ( P = 0.88) and reduced perceived fullness at 120 min during the OGTT ( P = 0.05). We conclude that 2 wk of exercise training intensity does not modulate appetite-regulatory hormones in obese adults with prediabetes. Although perceived fullness to the OGTT was reduced after exercise, CONT and INT decreased energy intake, suggesting that exercise does not elicit compensatory appetite behavior to gain weight. NEW & NOTEWORTHY Adults with prediabetes are at risk for appetite dysregulation. Although exercise promotes weight management, it is unclear whether moderate-continuous or high-intensity interval training is more beneficial for appetite regulation. We show that 2 wk of exercise, independent of intensity, does not alter postprandial appetite hormones or hunger, despite slight reductions in food intake and weight. These data support exercise as an effective method to induce negative energy balance without compensatory weight gain.
Keywords: GLP-1; appetite; energy intake; ghrelin; weight loss.