Very Low Calorie Ketogenic Diet: What Effects on Lipid Metabolism?

Abstract

Purpose of review: This review aims to critically examine how VLCKD affects plasma lipoprotein, lipid and cholesterol metabolism. Cardiovascular disease is a worldwide health problem affecting millions of people and leading to high rates of mortality and morbidity. There is a well-established association between cardiovascular disease and circulating cholesterol. Various dietary recommendations are currently available for the management of dyslipidemia.

Recent findings: The very low-calorie ketogenic diet (VLCKD) is becoming increasingly popular as a treatment option for several pathological conditions, including dyslipidemia. In addition to being low in calories, the VLCKD's main feature is its unique calorie distribution, emphasizing a reduction in carbohydrate consumption in favor of fat as the primary calorie source. Lowering calorie intake through a VLCKD can reduce the endogenous production of cholesterol. However, if the foods consumed are from animal sources, dietary cholesterol intake may increase due to the higher fat content of animal products. When combined, these dietary practices may have opposing effects on plasma cholesterol levels. Studies investigating the impact of VLCKD on plasma cholesterol and low-density lipoprotein cholesterol levels report contradictory findings. While some studies found an increase in low-density lipoprotein cholesterol levels, others showed a decrease in total cholesterol and low-density lipoprotein cholesterol, along with an increase in high-density lipoprotein cholesterol.

Keywords: Cholesterol; Dyslipidemia; Hypercholesterolemia; Lipid Metabolism; Low-density lipoprotein; Obesity; Very-low-calorie ketogenic diet.

Fig. 1

Disease states where VLCKD have been studied. Studies show decrease in fatty deposits in the liver in non-alcoholic liver disease. VLCKD induces weight loss and decreased appetite in obesity [6, 13, 40, 42, 57, 84, 85]. In type 1 diabetes, however, use of VLCKD is controversial due to the increase in ketone bodies that may be a common complication of the disease. In type 2 diabetes, findings are also controversial in regards to the regulation of Hb1Ac levels by a VLCKD [62, 64, 69, 70]. Finally, application of VLCKD in cancer and chronic kidney disease is still debated [27, 28, 52, 55]