Weight-loss diet that includes consumption of medium-chain triacylglycerol oil leads to a greater rate of weight and fat mass loss than does olive oil.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 18326600 · doi:10.1093/ajcn/87.3.621
What was done
Forty-nine overweight men and women aged 19–50 years (mean BMI 29.8 ± 0.4 kg/m²) consumed either 18–24 g/d of medium-chain triacylglycerol (MCT) oil or olive oil as part of a 16-week weight-loss program with weekly group counseling. Body weight and waist circumference were measured weekly. Adipose tissue distribution was assessed at baseline and endpoint using dual-energy X-ray absorptiometry and computed tomography.
What was found
Thirty-one subjects completed the study. MCT oil consumption resulted in lower endpoint body weight than olive oil (-1.67 ± 0.67 kg, unadjusted P = 0.013). There were non-significant trends toward greater loss of total fat mass (P = 0.071) and trunk fat mass (P = 0.10) with MCT oil. Endpoint trunk fat mass, total fat mass, and intra-abdominal adipose tissue were all lower in the MCT group compared to olive oil (all unadjusted P < 0.05).
Why it matters
Substituting medium-chain triacylglycerols for long-chain fats like olive oil during an energy-restricted diet can modestly improve body weight and central fat reduction over 16 weeks.
Limits
High attrition rate (18 of 49 participants, or 36.7%, did not complete the study), small final sample size (n = 31), reliance on unadjusted P-values, and lack of post-intervention weight maintenance follow-up.