BMI modifies the effect of dietary fat on atherogenic lipids: a randomized clinical trial. Issue 4 (19th June 2019)

• Record Type: Journal Article
• Authors: Sundfør, Tine Mejlbo; Svendsen, Mette; Heggen, Eli; Dushanov, Sasha; Klemsdal, Tor Ole; Tonstad, Serena
• Is Part Of: American journal of clinical nutrition. Volume 110:Issue 4(2019)
• Page Start: 832
• Page End: 841
• Publication Date: 2019-06-19
• Subjects: lipid response -- dietary fatty acids -- intervention study -- interaction with BMI -- PCSK9; Diet therapy -- Periodicals; Nutrition -- Periodicals; Dietetics -- Periodicals; 613.205
• DOI: 10.1093/ajcn/nqz113
• Languages: English
• ISSNs: 0002-9165

Abstract

ABSTRACT: Background: SFA intake increases LDL cholesterol whereas PUFA intake lowers it. Whether the lipid response to dietary fat differs between normal-weight and obese persons is of relevance to dietary recommendations for obese populations. Objectives: We compared the effect of substituting unsaturated fat for saturated fat on LDL cholesterol and apoB concentrations in normal-weight (BMI ≤ 25 kg/m 2 ) and obese (BMI: 30–45) subjects with elevated LDL cholesterol. Methods: We randomly assigned 83 men and women (aged 21–70 y) stratified by BMI (normal: n = 44; obese: n = 39) and elevated LDL cholesterol (mean ± SD, normal weight 4.6 ± 0.9 mmol/L; obese 4.4 ± 0.8 mmol/L) to either a PUFA diet enriched with oil-based margarine ( n = 42) or an SFA diet enriched with butter ( n = 41) for 6 wk. Results: Seven-day dietary records showed differences of ∼9 energy percent (E%) in SFA and ∼4 E% in PUFA between the SFA and PUFA groups. In the total study population, the PUFA diet compared with the SFA diet lowered LDL cholesterol (−0.31 mmol/L; 95% CI: −0.47, −0.15 mmol/L, compared with 0.32 mmol/L; 95% CI: 0.18, 0.47 mmol/L; P < 0.001) and apoB (−0.08 g/L; 95% CI: −0.11, −0.05 g/L, compared with 0.07 g/L; 95% CI: 0.03, 0.10 g/L; P < 0.001). Tests of the BMI × diet interaction were significant for total cholesterol, LDL cholesterol, and apoB ( P values ≤ 0.009). In normal-weight compared with obese participants post-hoc comparisons found that the respective changes in LDL cholesterol were 9.7% (95% CI: 5.3%, 14.2%) compared with 5.3% (95% CI: −0.7%, 11.2%), P = 0.206, in the SFA group, and −10.4% (95% CI: −15.2%, −5.7%) compared with −2.3% (95% CI: −7.4%, 2.8%), P = 0.020, in the PUFA group. ApoB changes were 7.5% (95% CI: 3.5%, 11.4%) compared with 3.0% (95% CI: −1.7%, 7.7%), P = 0.140, in the SFA group, and −8.9% (95% CI: −12.6%, −5.2%) compared with −3.8% (95% CI: −6.3%, −1.2%), P = 0.021, in the PUFA group. Responses to dietary fat were not associated with changes in polyprotein convertase subtisilin/kexin type 9 concentrations. Conclusions: BMI modifies the effect of PUFAs compared with SFAs, with smaller improvements in atherogenic lipid concentrations in obese than in normal-weight individuals, possibly supporting adjustment of dietary recommendations according to BMI. This trial was registered with www.clinicaltrials.gov as NCT02589769.