Relation of specific dynamic action of food (SDA) to growth in rats.

The relation between food induced thermogenesis and anabolic processes was investigated in normal and malnourished rats. The metabolic rate was measured 5 and 17 hr after food removal. The difference between the two measurements was 3.9% during growth arrest of malnourished rats gaining 0.6 g/day, but 20.0 and 28.7% during growth recovery when rats were gaining 4.1 and 5.3 g/day, respectively. The 5 hr postprandial metabolic rates rose in normal rats from 15.6 kcal/day at 4 weeks to 45.3 kcal/day at 15 weeks, and then declined to 38.5 kcal/day at 36 weeks. The difference between 5 and 17 hr postprandial metabolic rates was 28.8% in 5 to 15-week-old rats gaining 5.2 g/day, and 1.1% in 24 to 32-week-old rats who were no longer gaining weight.