Effects of very low-carbohydrate ketogenic diets on lipid profiles in normal-weight (body mass index < 25 kg/m²) adults: a meta-analysis.

This meta-analysis examines the effects of ketogenic diets (KDs)—defined as very low-carbohydrate diets with carbohydrate intake ≤10% of daily energy or 20–50 g/day—on lipid profiles in normal-weight adults (body mass index < 25 kg/m²) based on three randomized controlled trials. The findings indicate that KDs significantly increase total cholesterol, low-density lipoprotein cholesterol (LDL-C), and apolipoprotein B (apoB), while also raising high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A (apoA) levels compared with control diets; triglyceride levels showed inconsistent changes. The study highlights that although increased HDL-C may partially offset adverse lipid changes, normal-weight individuals should be cautious about the risk of hypercholesterolemia when following a KD. Due to the small number of studies and heterogeneity among them, the certainty of evidence is generally low to moderate, underscoring the need for further research on KDs' lipid effects in this population.