A Case of Hypoglycemia Associated With the Ketogenic Diet and Alcohol Use

Christopher Spoke and Samar Malaeb


J Endo Soc. 2020;4(6) 

In This Article

Abstract and Introduction


The ketogenic diet, which has become an increasingly popular diet, severely restricts carbohydrate intake to shunt metabolism towards fatty acid oxidation and production of ketones as a fuel source. There have been many studies illustrating the positive effects of a ketogenic diet in weight loss and other benefits; however, the long-term effects and potential adverse events of a ketogenic diet have not been well studied or documented in literature. There are a few case reports of ketogenic diet resulting in hypoglycemia. We report a case of hypoglycemia with a blood glucose of 39 mg/dL and ketosis in a 69-year-old woman who strictly followed a ketogenic diet for nearly one year. She presented with malaise, sugar cravings, and mental fogginess, and after intake of alcoholic beverages, was admitted to the hospital with hypoglycemia. She had elevated beta-hydroxybutyrate, and low insulin and C-peptide, all consistent with a starvation ketosis. This case illustrates that adherence to a ketogenic diet for a prolonged period of time, in combination with alcohol intake, can disrupt normal glucose homeostatic mechanisms and result in a significant degree of hypoglycemia. This pattern of hypoglycemia may not present with classic symptoms, most likely partly due to effects of the ketogenic diet on brain function. This case provides insight that supports the need to counsel patients about alcohol intake while on the ketogenic diet. More information is needed on long-term complications of the ketogenic diet on glucose homeostasis in the body as well as in the brain.


The ketogenic diet is a diet that has become increasingly popular over the past few decades. Initially studied for the treatment for epilepsy in the early 1900s, it has recently gained popularity for weight loss.[1] There are different variations of low-carbohydrate diets that range in carbohydrate intake, and that were popularized by South Beach and Atkins diet. A ketogenic diet is specifically a low-carbohydrate, high-fat diet that aims for a goal of 20 to 50 g of carbohydrate per day, and if possible, no more than 20 g of carbohydrates.[2] This results in a low insulin:glucagon ratio, which causes depletion of glucose and glycogen stores, and reliance on ketone bodies from fatty acids as alternative source of fuel, resulting in ketogenesis, referred to in the diet as achieving a state of ketosis. This occurs through the hepatic oxidation of fatty acids. An excess of ketones can result in ketonemia and in some instances, ketoacidosis.

There have been different studies that have shown that the ketogenic diet is overall safe in the short term; however, it is not without risk or adverse side effects.[2] There have been a few case reports and case series of individuals developing hypoglycemia due to the ketogenic diet, with most of those reported in children.[3–5] We present a case of a woman who developed starvation ketosis with hypoglycemia while on a ketogenic diet after the consumption of alcohol. We discuss the adverse effects of the ketogenic diet including hypoglycemia and risks of starvation ketosis.