Extreme Hypercholesterolemia Following a Ketogenic Diet: Exaggerated Response to an Increasingly Popular Diet.

A high-fat, very low-carbohydrate diet, often named the "ketogenic diet," is gaining popularity, particularly among patients with obesity and metabolic syndrome seeking rapid weight loss and improvement in glycemic control. A favorable reduction in triglycerides and an increase in high-density lipoprotein-cholesterol levels is often observed in the ketogenic diet. However, people vary significantly in their low-density lipoprotein-cholesterol (LDL-C) response to the dietary change. Here, we present the case of a 38-year-old normal-weight male with average cholesterol levels showing an extreme fourfold elevation in LDL-C levels, reaching 496 mg/dL after initiating a ketogenic diet. We highlight that a dramatic elevation in LDL-C may manifest following a ketogenic diet in normal-weight people without known genetic dyslipidemias before the dietary change; therefore, increased awareness and close monitoring of blood lipid profile is essential for all individuals following a ketogenic diet. We further discuss the potential mechanisms for the "lean mass hyper-responders" phenotype which has been recently gaining recognition, and suggest that these patients may benefit from ezetimibe therapy, decreasing the absorption of intestinal cholesterol to the liver.