Abstract

Energy expenditure (EE) during exercise and recovery was compared after consumption of a 500 kilocalories (kcal) (2100 kJ) meal, a 100 kcal (4200 kJ) meal and while in a 12 hour postprandial state. Subjects were four obese and two nearly obese female volunteers. Mean (+/- SD) age and percent fat were 29.3 +/- 58 years and 37.7 +/- 8 percent, respectively. Subjects walked for 30 minutes on a treadmill at 40 percent VO2max while in a fasting state, one hour after a 500 kcal meal and one hour after a 1000 kcal meal. Energy expenditure was assessed using indirect calorimetry for 30 minutes during exercise and 50 minutes of recovery. Mean EE during exercise was nearly identical in the fasted state as compared to the fed state (p>.05). Mean kcal/min (+/-SD) expended during recovery was significantly greater (p<.05) for the fed state as compared to the fasting state with values of 1.46 +/- 0.15 (6.1 +/- 0.6 kJ), 1.61 +/- 0.16 (6.8 +/- 0.7 kJ) and 1.69 +/- 0.14 (7.1 +/- 0.6 kJ) for the fasting, 500 kcal and 1000 kcal conditions, respectively. It was concluded that ingesting 500 or 1000 kcal of food before exercise does not increase EE during activity, but increases EE during the first hour of exercise recovery by 8.6 and 13.7 percent, respectively, compared to exercising in a fasting state. However, the added energy expenditure was small and would be of little benefit for weight control. Verf.-Referat