Atherogenic changes in postprandial lipoprotein subclass particle size and concentration after a restricted carbohydrate, high fat meal vs a high carbohydrate, low fat meal

Abstract

Postprandial lipemia is an atherogenic state caused by dietary fat. Restricted carbohydrate, high fat (RCHF) diets promote weight loss, but may qualitatively exacerbate postprandial lipemia. To test this hypothesis, acute effects of RCHF and high complex carbohydrate, low fat (HCLF) meals on lipoprotein subclass particle size (PS) and particle concentration (PC) were assessed in 16 weight-stable, obese adults. Meals provided 9 kcal/kg; the RCHF macronutrient profile was 45% fat, 30% protein, and 25% carbohydrate; the HCLF meal composition was 27% fat, 18% protein, and 55% carbohydrate. Plasma lipoprotein subclass PS and PC were measured by NMR spectroscopy before and 2, 4, 6, and 8 hr after eating the meal. Time and group effects were compared using MANOVA. Differences in 8 hr integrated area under the curves (AUC) were assessed with t-tests. Triglyceride AUCs were comparable after RCHF and HCLF meals. The AUC of IDL-PC was higher after the RCHF vs HCLF meal (151 ± 285 vs −222 ± 194 nmolhr/ L, p<0.008). AUC of VLDL-PS was higher (77 ± 23 vs 40 ± 23 nmhr, p<0.006) and VLDL-PC was lower −49 ± 120 vs 119 ± 89 nmol-hr/L, p<0.007) after RCHF vs HCLF meals, due in part to lower small VLDL-PC (−170 ± 108 vs −0.7 ± 90 nmol-hr/L, p< 0.004) after RCHF. In summary, these results suggest that a RCHF meal caused more atherogenic postprandial lipoprotein changes vs a HCLF meal. Long term studies are required to assess these adverse effects after chronic consumption of RCHF diets during weight loss maintenance. Funded by RO1 AT001930-01 A1 and 5 MO1 RR000334.