Weight-loss diets with varying proportions of macronutrients have had varying effects on weight loss, and components of metabolic syndrome and risk factors for vascular diseases. However, little work has examined the effect of weight-neutral dietary changes in macronutrients on these factors. This is an investigation using the OMNI Heart datasets available from the NHLBI BioLINCC program. This study compared a DASH-like diet high in carbohydrates with similar diets high in protein and high in unsaturated fats. Measures of metabolic syndrome, except waist, and measures of risk factors for vascular diseases were taken at the end of each dietary period. All 3 diets significantly lowered the number of metabolic syndrome components (p ≤ 0.002) with a standardized measure of changes in metabolic syndrome components, suggesting that the high-protein, high-fat diet was most efficacious overall (p = 0.035). All 3 diets lowered a calculated 10-year risk of cardiovascular disease, with the high-protein and unsaturated fat diet being the most efficacious (p < 0.001). Only the unsaturated fat diet showed a slightly decreased calculated 9-year risk of diabetes (p = 0.11). Of the 3 weight-neutral diets, those high in protein and unsaturated fats appeared partially or wholly most beneficial.
Keywords: OMNI Heart; cardiovascular disease risk; diabetes risk; dietary carbohydrates; dietary proteins; dietary unsaturated fats; metabolic syndrome.