Although effective for losing weight in short periods of time, this restrictive diet can cause annoying side effects and significant dietary imbalances. Because it is not sustainable in the long term, it exposes you to greater weight gain when you return to a normal diet (“yo-yo effect”). In the management of certain chronic diseases (particularly drug-resistant childhood epilepsy), the ketogenic diet has not been proven in terms of scientifically reliable data.
What is the “ketogenic diet”?
The so-called “ketogenic” (or “keto”) diet is a slimming diet based on the almost complete elimination of carbohydrates (sugars and starches) from the diet: less than 50 grams per day, or 6 times less than the average for a balanced diet. To provide the calories necessary for life, it is then essential to consume more proteins and, above all, fats (lipids). To simplify, we eat fat to lose weight, by eliminating sugars and starches!
The ketogenic diet is not only proposed for weight loss. It is also touted for its benefits in the management of certain chronic diseases, particularly epilepsy in children but also cancers, Alzheimer’s disease or chronic inflammatory diseases (Crohn’s disease, polyarthritis, spondylitis, etc.).
What are the mechanisms of the ketogenic diet?
In this type of diet, the body must adapt to produce the glucose (sugar) necessary for its functioning, despite the low amount of carbohydrates in the diet. The liver will produce it from fats (consumed or present in the body) but also from glycogen reserves (a molecule used to store glucose in the liver and muscles). This mechanism is triggered in 48 hours when the intake of dietary carbohydrates disappears.
This change in diet is effective in burning body fat (unless of course you eat too much fatty food!) and weight loss is quickly observed, up to several kilograms in a month.
What are the dangers of the ketogenic diet?
The ketogenic diet can cause unpleasant side effects: nausea, constipation, fatigue, headaches, cramps, bad breath, and even kidney stones. In addition, it can cause dehydration if the person does not drink more than usual (at least 2 liters per day). In addition, eliminating fruits and certain vegetables exposes you to the risk of deficiencies in mineral salts, vitamins, trace elements and fiber (which harms transit and intestinal flora).
In addition, in the case of a ketogenic diet, it is essential to preferentially consume vegetable fats (oils, in particular those with a high concentration of omega-3 fatty acids such as linseed oil or camelina oil, nuts, avocados, etc.) rather than animal fats (butter,
What do you think of the ketogenic diet in the management of certain diseases?
For a century, the ketogenic diet has been proposed to reduce the frequency of epileptic seizures in children who are resistant to standard treatments, without any real experimental evidence. Doctors had observed a decrease in seizures in children forced to fast for other reasons. For this reason, the ketogenic diet is sometimes implemented in children whose epilepsy worsens despite medication. It requires very strict medical monitoring. This use of the ketogenic diet lost its credibility when a cross-analysis of clinical trials on the subject was published in 2020 by the Cochrane network, an analysis which showed little benefit and highlighted the adverse effects of this diet (diarrhea, constipation and vomiting) and the difficulty for parents of epileptic children to implement it sustainably. Nevertheless, it is still sometimes prescribed to severely epileptic children who are resistant to treatment.
In the field of cancer, specialists formally advise against the ketogenic diet, which could theoretically aggravate, via an exacerbation of inflammation, the spread of metastases. In 2018, a cross-analysis of 11 clinical studies conducted on the action of the ketogenic diet in cancer was published in the Journal of Human Nutrition and Dietetics: it concluded that there was no convincing evidence.
In conclusion , the ketogenic diet is a weight loss strategy that, while it has visible effects quickly, is not sustainable over time due to its side effects and its long-term health consequences. Like all restrictive diets, the ketogenic diet exposes you to a yo-yo effect when you stop following it. For all these reasons, nutritionists advise against the ketogenic diet and prefer to opt for a dietary rebalancing that includes all food families, which is easier to follow over time and, ultimately, more effective. Its use in the management of various chronic diseases is not based on any scientific evidence of reliable effectiveness.