Consumption of alpha-linolenic acid-enriched diacylglycerol induces increase in dietary fat oxidation compared with alpha-linolenic acid-enriched triacylglycerol: A randomized,double-blind trial

Fat metabolism is an important consideration in obesity. Alpha-linolenic acid-enriched diacylglycerol (ALA-DAG), which mainly occurs as ALA esterifies to 1,3-diacyl-sn-glycerol (1,3-DAG), has beneficial effects on fat metabolism and body weight compared with triacylglycerol (TAG). Moreover, compared with ALA-TAG, ALA-DAG enhances β-oxidation activity in the small intestine and liver in rodents. We hypothesized that ALA-DAG consumption may increase dietary fat oxidation compared with ALA-TAG in humans. To examine this hypothesis, we conducted a randomized double-blind cross-over trial in 17 normal and moderately obese men and women (BMI: 25.7 ± 2.0 kg/m², mean ± SD). Each participant was assigned to a 4-week intervention period with 2.5 g/day of ALA-DAG or ALA-TAG consumption, followed by a 4-week washout period between consumption of each diet. Dietary fat oxidation, assessed based on the ¹³CO₂ recovery rate in the breath, was significantly increased by ALA-DAG consumption compared with ALA-TAG consumption (17.0 ± 4.5% and 14.1 ± 5.9%, respectively, P < .05). In addition, ALA-DAG consumption significantly decreased the visceral fat area compared with ALA-TAG (102.9 ± 51.9 cm² and 110.9 ± 51.7 cm², respectively; P < .05). These results indicate that ALA-DAG consumption may be useful for preventing obesity.