Short‐term Changes in Lipoprotein Subclasses and C‐reactive Protein Levels with the Low Carbohydrate and Low‐Fat Diets

Background: Diets designed to promote weight loss and improve atherogenic lipid profiles traditionally include a reduction in total fat and in particular, saturated fats. This study was designed to test the efficacy of a low‐fat diet vs. a carbohydrate restricted (low‐CHO) diet in hypertriglyceridemic patients on lipid profile, weight loss, C‐reactive protein (CRP) and satiety. Methods: Twenty‐eight hypertriglyceridemic subjects (with fasting triglyceride (TG) levels exceeding 1.69 mmol/L) were randomized to either the low‐CHO or low‐fat diet for 8 weeks. Fasting bloods were drawn at weeks 0 and 8 and analyzed for lipids via NMR and CRP. Anthropometric measurements were also obtained. Three random 24‐hr food recalls were used to assess compliance during the trial. Results: Based on the 23 subjects who completed the protocol, small LDL particles of the low‐CHO subjects fell by 46% after 8 weeks, while those on the low‐fat plan exhibited an increase (36.5%), p=0.045. An average decrease in TG of 18% among low‐CHO subjects in contrast to an increase of 4% for low‐fat group was not significantly different. Nor were there significant differences in CRP, overall dietary compliance, satiety or the magnitude of body weight lost between groups (low‐CHO group, −3.8% vs low‐Fat group, −1.6%). Conclusion: Favorable reductions in small LDL concentrations after 8 weeks suggest that a moderately restricted carbohydrate diet (less than 20% CHO as energy) can promote a healthier, less atherogenic lipid profile when compared to the low‐fat diet.