Effects of fasting and refeeding on the metabolic response to a standard meal in man.

Measurements of resting and exercising metabolic rate were made on eight subjects (five male, three female) before and after consumption of a standard liquid meal (1.67 MJ). This test was conducted after a day of complete fast and again after a day of overeating (average intake, 19.8 MJ). There were no significant changes in resting or exercising metabolic rate due to the previous day's energy intake. The resting thermic effect (post-prandial rise in metabolic rate) of the standard meal was similar on both test days but the exercising thermic effect was 50% greater after the day of overeating. It was concluded that the metabolic response to food in exercising subjects may be affected by the previous day's energy intake but the overall energetic efficiency of the body at rest and during exercise is unaffected.