Effects of diacylglycerol on postprandial energy expenditure and respiratory quotient in healthy subjects

Objective This study examined the effects of a diacylglycerol (DAG)-containing diet on postprandial energy expenditure and respiratory quotient. Methods A randomized, double-blind, crossover, placebo-controlled study with a washout period was performed in 13 healthy male subjects. A 4240-kJ diet containing 30 g of triacylglycerol (TAG) or DAG (TAG meal or DAG meal, containing 34.5% lipids, 52.1% carbohydrates, and 14.1% proteins) was administered after a fasting period of 15 to16 h. Breath and serum were analyzed for up to 5 h after ingestion of the meal. Results The amount of change in energy expenditure 3 h after loading with the DAG meal tended to be higher than that after loading with the TAG meal (P < 0.1). Changes in respiratory quotient 2 and 5 h after loading with the DAG meal were significantly lower than those after loading with the TAG meal, suggesting high lipid oxidation activity after the meal. The serum insulin level 0.5 h after loading with the DAG meal was significantly lower than that after loading with the TAG meal. This result suggests that there is a smaller stimulus in the direction of fat storage after loading with the DAG meal. Conclusions Compared with the TAG-containing meal, the DAG-containing meal tended to produce a higher postprandial energy expenditure and a significantly lower postprandial respiratory quotient. These results suggest that the DAG-containing meal has high postprandial lipid oxidation activity and a potential effect on high diet-induced thermogenesis.