Evaluating the differential benefits of varying carbohydrate-restricted diets on lipid profiles and cardiovascular risks in dyslipidemia: a meta-analysis and systematic review

Background: carbohydrate-restricted diets (CRDs) have gained attention to address metabolic dysregulation commonly observed in dyslipidemia, a condition posing significant risks to cardiovascular health. However, the effectiveness of CRDs in improving cardiovascular health remains contentious. This meta-analysis comprehensively evaluated the long-term effects of CRDs on glucolipid metabolism and weight loss in individuals with dyslipidemia. Methods: extensive searches were conducted in PubMed, Web of Science, Scopus, the Cochrane Library, and EMBASE. Randomized controlled trials examining the effects of CRDs on glucolipid metabolism and weight loss in adults with dyslipidemia over a minimum of three weeks were included. This analysis compared the differential effects between moderate-low carbohydrate diets (MLCDs) and low carbohydrate diets (LCDs), including a targeted evaluation of animal-based CRDs and dyslipidemic individuals based on the BMI status, thereby addressing gaps in current knowledge. Results: Our findings indicated that CRDs significantly enhanced lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and apolipoprotein B (ApoB), and contributed to weight management in individuals with dyslipidemia. MLCDs were more effective than LCDs in improving all lipid profiles except for TG, which was more effectively managed by LCDs. Animal-based CRDs did not significantly impact lipid profiles. Dyslipidemic individuals with overweight and obesity showed significant changes in TG and ApoB. A noteworthy negative correlation was also observed between TC, TG, and low-density lipoprotein cholesterol levels with higher dietary fiber intake, supporting the beneficial impact of fiber on cardiovascular health. Conclusions: These results for the first time highlighted the potential of adopting MLCDs, particularly those with sufficient fiber content, as a powerful strategy for reducing the risk of cardiovascular diseases in patients suffering from dyslipidemia.