Abstract/Summary

Background: Diets high in saturated fatty acids (SFAs) and greater abdominal obesity are both associated with raised low-density lipoprotein cholesterol (LDL-C) concentrations, an independent cardiovascular disease (CVD) risk marker. Although reducing SFA intake is a public health strategy for CVD prevention, the role of body fat distribution on the relationship between SFA and LDL-C is unclear. Therefore, our objective was to investigate whether the association between dietary SFAs and LDL-C concentrations is related to body composition. Methods: In the BODYCON (impact of physiological and lifestyle factors on body composition) study, 409 adults (mean age 42±16y and median BMI of 23.5 (21.5-25.9) kg/m2) underwent a measure of body composition by dual energy x-ray absorptiometry, assessment of habitual dietary intake using a 4-day weighed food diary and physical activity level using a tri-axial accelerometer. Blood pressure was measured, and a fasting blood sample was collected to determine cardiometabolic disease risk markers. Correlations between body composition, circulating risk markers and dietary macronutrients were assessed prior to multivariate regression analysis. The effect of increasing intakes of dietary SFA on outcome measures was assessed using ANCOVA after adjusting for covariates. Results: Abdominal visceral adipose tissue (VAT) mass was moderately positively correlated with total cholesterol (TC), LDL-C, systolic blood pressure (SBP), diastolic blood pressure and HOMA-IR (rs=0.25-0.44, p<0.01). In multiple regression analysis, 18.3% of the variability in LDL-C was explained by SFA intake (% total energy (TE)), abdominal VAT mass, carbohydrate%TE and fat%TE intakes. When data were stratified according to increasing SFA%TE intakes, fasting TC, LDL-C and non-high-density lipoprotein-cholesterol were higher in Q4 compared with Q2 (p≤0.03). SBP was higher in Q4 versus Q3 (p=0.01). Android lean mass was also higher in Q3 versus Q1 (p=0.02). Other anthropometric and CVD risk markers were not different across quartile groups. Conclusions: Although dietary SFA was found to explain 9% of the variability in LDL-C, stratification of data according to quartiles of SFA intake did not reveal a dose-dependent relationship with LDL-C concentration. Furthermore, this association appeared to be independent of abdominal obesity in this cohort.