ABSTRACT
Inflammation plays a crucial role in the pathogenesis and progression of type II diabetes, atherosclerosis, cardiovascular disease and metabolic syndrome [MetS]. Despite high prevalence of MetS and its strong association with other chronic inflammatory diseases, the optimal dietary macronutrient composition to manage the inflammatory process in the MetS remains unknown. We aimed to review the evidence on the effects of variation in dietary macronutrient intakes on chronic inflammation in the MetS. We searched PubMed/MedLine between 1990 and 2011,using the following keywords: macronutrient, high/low-carbohydrate,-fat,-protein, ketogenic, metabolic syndrome, chronic inflammation, and the surrogate inflammatory biomarkers. Clinical trials and cross-sectional and prospective studies were included in this investigation. Dietary intakes of trans-fatty acids have been associated with elevated levels of inflammatory indices. Although strict restriction of dietary carbohydrates [ketogenic diet] has affected inflammatory biomarkers considerably, moderately-restricted carbohydrate diets were not different from low-fat diets in terms of their impacts on inflammation. High-protein diets do not seem to be suitable for alleviating inflammation, because of their probable deleterious effects on liver and kidney functions. Sever restriction of dietary carbohydrates [similar to ketogenic diets] seems to be essential if one intends to influence the inflammatory process in the metabolic syndrome; moderate dietary carbohydrate restriction does not seem to affect inflammation. Lack of sufficient evidenceon the subject in different groups of patients and limitations in the design of current studies warrants further investigation in this field