Role of Dietary Fats in Modulating Cardiometabolic Risk During Moderate Weight Gain: A Randomized Double-Blind Overfeeding Trial (LIPOGAIN Study)

Study Questions:

Does the type of dietary fat alter cardiometabolic response and atherogenic markers to a hypercaloric diet?

Methods:

A 7-week, double-blind, parallel-group, randomized, controlled trial was conducted in 39 healthy, lean individuals (mean age 27 ± 4). Participants consumed muffins (51% of energy [%E] from fat and 44%E refined carbohydrates) providing 750 kcal/day added to their habitual diets. All muffins had identical contents, except for type of fat; sunflower oil rich in polyunsaturated fatty acids (PUFA diet) or palm oil rich in saturated fatty acids (SFA diet).

Results:

Despite comparable weight gain in the two groups, total:high-density lipoprotein (HDL) cholesterol, low-density lipoprotein:HDL cholesterol, and apolipoprotein B:AI ratios decreased during the PUFA versus the SFA diet (-0.37 ± 0.59 vs. +0.07 ± 0.29, -0.31 ± 0.49 vs. +0.05 ± 0.28, and -0.07 ± 0.11 vs. +0.01 ± 0.07, p = 0.003, p = 0.007, and p = 0.01 for between-group differences), whereas no significant differences were observed for other cardiometabolic risk markers. In the whole group (i.e., independently of fat type), body weight increased (+2.2%, p < 0.001) together with increased plasma proinsulin (+21%, p = 0.007), insulin (+17%, p = 0.003), proprotein convertase subtilisin/kexin type 9, (+9%, p = 0.008) fibroblast growth factor-21 (+31%, p = 0.04), endothelial markers vascular cell adhesion molecule–1, intercellular adhesion molecule–1, and E-selectin (+9, +5, and +10%, respectively, p < 0.01 for all), whereas nonesterified fatty acids decreased (-28%, p = 0.001).

Conclusions:

The authors concluded that excess energy from PUFA versus SFA reduces atherogenic lipoproteins. Modest weight gain in young individuals induces hyper-proinsulinemia and increases biomarkers of endothelial dysfunction, effects that may be partly outweighed by the lipid-lowering effects of PUFA.

Perspective:

Sunflower oil is a monounsaturated (MUFA)/polyunsaturated (PUFA) mixture of a mostly oleic acid (omega-9)-linoleic acid (omega-6) group of oils. While the study is valid, the application to common food preparation in the United States is not direct. Similar studies are necessary using PUFA and SFA with low glycemic index carbohydrates, which are used in commercially available ‘healthy muffins.’

Clinical Topics: Dyslipidemia, Heart Failure and Cardiomyopathies, Prevention, Lipid Metabolism, Nonstatins, Novel Agents, Statins, Heart Failure and Cardiac Biomarkers, Diet

Keywords: Vascular Cell Adhesion Molecule-1, Insulin, Atherosclerosis, Food Habits, E-Selectin, Dietary Fats, Body Weight, Proinsulin, Glycemic Index, Oleic Acid, Fibroblast Growth Factors, Weight Gain, Apolipoproteins B, Proprotein Convertases, Carbohydrates, Cholesterol, Intercellular Adhesion Molecule-1, Plant Oils, Subtilisins, Linoleic Acid, Fatty Acids, Unsaturated, Diet, Fatty Acids, Nonesterified


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