Meal fatty acid metabolism is associated with long-term weight gain in females—a retrospective cohort study

Background There have been multiple attempts to identify biological factors that predict long-term weight change. Previous investigators have theorized that variations in how humans metabolize dietary macronutrients (storage as opposed to oxidation) might be one of these characteristics, but to date there has been no effort to address this hypothesis. Objective We used a retrospective cohort study design to test the hypothesis that greater meal fat storage in subcutaneous adipose tissue would be associated with greater future weight gain. Methods Body composition, demographic, and meal fatty acid metabolism data was collated from 154 non-obese research volunteers who participated in studies conducted at Mayo Clinic between 1997 and 2012 that used either 14 C- or 3 H-triolein. At the time of the original studies, the participants were healthy, weight-stable, free of acute illnesses, and not taking any drugs that could affect the study outcomes. Using an electronic medical record search strategy, we identified satisfactory post-study weight data for 107 volunteers (54 males), over a mean follow up of 18 years. Regression analysis was used to test for relationships between adipose tissue meal fatty acid storage (and oxidation) and annualized weight change. Results The long-term (19 ± 7) years weight change for females was correlated with meal fat storage ( P = 0.003, r=0.38) and meal fat oxidation measured using 14 C-triolein (43 females P = 0.03, r = - 0.33). There was no significant relationship between meal fatty acid storage or oxidation and weight change for males. Conclusions The finding that weight change is correlated with dietary fatty acid metabolism for adult, non-obese females suggests that inter-individual variations in how women process dietary fat can influence long-term energy balance. Clinical Trial Registration NCT00254371; the other protocols were not considered clinical trials at the time they were conducted. https://clinicaltrials.gov/study/NCT00254371?term=testosterone&cond=%22Sarcopenia%22&viewType=Table&rank=9