Diets with differing macronutrient profiles elicit differential changes in lipid ratios, specifically TC:HDL‐C and TG:HDL‐C

Ratios of total cholesterol (TC) to high‐density‐lipoprotein cholesterol (HDL‐C) and triglycerides (TG) to HDL‐C are good predictors of cardiovascular disease (CVD) risk. A free‐living weight (wt)‐loss study was used to compare the effects of a moderate‐protein (1.5 g/kg), reduced‐carbohydrate (38%) diet (PRO) and a low‐protein (0.7 g/kg), high‐carbohydrate (60%) diet (CHO) on wt loss and lipids and lipoproteins. Adults (N=36, 18 M, 18 F) were randomly assigned to CHO or PRO diets. Following rapid wt loss (4 mo), TC decreased in the CHO group (P<0.01); this change was not sustained during wt maintenance (12 mo). Compared to baseline, HDL‐C was higher at 4 mo in the PRO group (P<0.05) and at 12 mo in both groups (P<0.001). Thus, TC:HDL‐C was lower in the PRO group at the end of rapid wt loss (P<0.01) and in both the PRO (−22%) and CHO (−18%) groups at the end of wt maintenance (P<0.001). At 4 and 12 mo, TG decreased in the PRO group (P<0.001); the decrease in TG in the CHO group approached significance at 12 mo (P=0.06). As a result, TG:HDL‐C was lower in both groups at 12 mo (P<0.05) compared to baseline; this change was greater in the PRO group (5.3 to 1.7, −59%) compared to the CHO group (3.8 to 2.2, −38%; P=0.01), thereby resulting in a greater CVD risk reduction. This demonstrates the importance of assessing lipid ratios, such as TC:HDL‐C and TG:HDL‐C, in addition to individual lipid levels when comparing diets with differing macronutrient profiles on CVD risk. Supported by Natl. Cattlemen's Beef Assoc. & Kraft Foods.