Metabolic responses to 8 weeks of consuming cottonseed oil versus olive oil in adults with dyslipidaemia: a randomised trial.

Background: Differences in metabolic responses between diets rich in monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) could affect energy balance and weight maintenance. The present study was a secondary analysis to investigate 8‐week diet interventions rich in either PUFA (cottonseed oil [CSO]) or MUFA (olive oil [OO]) on metabolic responses in adults with dyslipidaemia. Methods: Forty‐one adults with dyslipidaemia completed this randomised trial consisting of an 8‐week partial‐outpatient feeding trial. Provided foods accounted for about 60% of their daily energy needs, with about 30% of energy needs provided by CSO (n = 20) or OO (n = 21). At pre‐ and postdiet intervention visits, participants consumed a high saturated fatty acid (SFA) meal (35% daily energy needs, 47.9% from SFA), and fasting and 3.5‐h postprandial indirect calorimetry were used to measure energy expenditure (EE) and substrate oxidation. Results: No changes were observed in fasting measures. The OO group had greater increases in postprandial EE (p = 0.002); however, there were no differences in substrate oxidation between groups. A lack of metabolic flexibility was found in both groups, which was partially explained by changes in insulin sensitivity (homeostasis model assessment of insulin resistance). Conclusions: The results of the present study show that OO, but not CSO, diet enrichment improves EE after an occasional high SFA meal, which may improve weight maintenance over time. This study is registered at clinicaltrials.gov (NCT04397055). Key points: An olive‐oil‐enriched diet may improve postmeal energy expenditure more than a cottonseed‐oil‐enriched diet.Exploratory analysis suggests that changes in insulin resistance (homeostasis model assessment of insulin resistance) may contribute to one's ability to adapt to a high‐fat diet. [ABSTRACT FROM AUTHOR]