This article presents a summary of the key points of the conference given on June 3, 2021 as part of the seminar “Cardiology in Everyday Life” (in French) organized by Médecins francophones du Canada in partnership with the Montreal Heart Institute.
The ketogenic diet has been used for a long time to treat epilepsy in children. It is very low in carbohydrates (20g of net carbohydrates per day) and very high in fat (70 to 75% of the total energy intake). Carbohydrates while on the diet come mainly from low-carb vegetables. Fruits, whole grains, vegetables which are higher in carbohydrates, and beans are excluded. The lack of carbohydrates causes depletion of the liver glycogen stores within 24 to 36 hours and the production of ketone bodies via neoglucogenesis which are the only source of energy for the brain. The strict ketogenic diet has certain risks including a possible deficiency in certain nutrients, insufficient fiber intake, a negative impact on the gut microbiota, an increased risk of colon cancer, and a potential risk for those taking certain medications such as insulin or having certain health conditions.
It consists of a low-carb, high-fat diet, but is less restrictive than the ketogenic diet. It allows a consumption of 50 to 100g of net carbohydrates per day (about 20 to 30% of the total energy intake versus 50% for a traditional diet). There is no ketone bodies production, and no food is prohibited.
Low-carb diets can induce rapid weight loss in the short term (6 months and less), but include a loss of water and muscle mass. The long-term effects on weight loss are not well known and the long-term adherence is low. In the long term (6 months to 5 years), these diets are not more effective for weight loss than a low-fat or Mediterranean diet with caloric restriction.