Clinical and lipid metabolic responses to diacylglycerol oil administration in Chinese adults with overweight/obesity or central obesity: a randomized, double-blind, placebo-controlled trial

Abnormalities in triacylglycerol metabolism can lead to excessive visceral fat accumulation. Though diacylglycerol (DAG) administration could reduce serum total triacylglycerol (TG), its impact on visceral fat deposition and potential mechanisms remains unclear. This trial aimed to evaluate the impact of substituting regular rapeseed cooking oil (TAG) with DAG oil on primary outcomes such as anthropometric measurements and lipid profiles, as well as secondary outcomes including visceral fat and serum lipidomics in Chinese adults with overweight/obesity or central obesity. Ninety-five participants (BMI: 25.93 ± 2.92 kg m^-2) were assigned to the DAG or TAG group through random allocation. Over 8 weeks, participants were provided similar diets cooked with DAG or TAG oil, respectively. By week 8, the serum TG (<i>P</i> = 0.026) and small dense low-density lipoprotein cholesterol (sdLDL-C) (<i>P</i> = 0.024) levels in the DAG group were significantly lower than those in the TAG group. The change in sdLDL-C was notably greater in the DAG group than in the TAG group (-0.10 ± 0.12 <i>vs.</i> -0.03 ± 0.16), and a significant decrease in the levels of waist circumference, hip circumference, total cholesterol, and sdLDL-C was only observed in the DAG group compared with the baseline (all <i>P</i> < 0.05). Imaging analyses revealed that attenuation of hepatic steatosis was observed in the DAG group compared with the TAG group (<i>P</i> = 0.035), and a decrease in visceral fat area was found only in the DAG group compared with the baseline (<i>P</i> < 0.001). Lipidomic profiling demonstrated DAG induced enrichment of serum triacylglycerol and phosphatidylethanolamine species containing mono/polyunsaturated fatty acids, which were associated with the enhanced adipocyte lipolysis and thermogenesis. These findings suggested that DAG-mediated lipid remodeling might be related to preventing lipid metabolic disorders through visceral fat regulation.