Appropriately tailored diet regimens for weight reduction can help manage the obesity epidemic to some extent. One diet regimen that has proven to be very effective for rapid weight loss is a very low-carbohydrate and high-fat ketogenic diet. Russel Wilder first used the ketogenic diet to treat epilepsy in 1921. He also coined the term “ketogenic diet.”
A ketogenic diet primarily consists of high fats, moderate proteins, and very low carbohydrates. The dietary macronutrients are divided into approximately 55% to 60% fat, 30% to 35% protein, and 5% to 10% carbohydrates. Specifically, in a 2000 kcal per day diet, carbohydrates amount up to 20 to 50 g per day.
A period of low carbohydrate ketogenic diet may help to control hunger and may improve fat oxidative metabolism and therefore reduce body weight. Furthermore, new kinds of ketogenic diets using meals that mimic carbohydrate-rich foods could improve compliance to the diet. Attention should be paid to the patient’s renal function and to the transition phase from the ketogenic diet to a normal diet that should be gradual and well-controlled. The duration of the ketogenic diet may range from a minimum (to induce the physiological ketosis) of 2–3 weeks to a maximum (following a general precautionary principle) of many months (6–12 months).
Some negative side effects of a long-term ketogenic diet have been suggested, including increased risk of kidney stones and osteoporosis, and increased blood levels of uric acid (a risk factor for gout). Possible nutrient deficiencies may arise if a variety of recommended foods on the ketogenic diet are not included. It is important to not solely focus on eating high-fat foods but to include a daily variety of the allowed meats, fish, vegetables, fruits, nuts, and seeds to ensure adequate intakes of fiber, B vitamins, and minerals (iron, magnesium, zinc)—nutrients typically found in foods like whole grains that are restricted from the diet. Because whole food groups are excluded, assistance from a registered dietitian may be beneficial in creating a ketogenic diet that minimizes nutrient deficiencies.
Cautions and Contraindications:
People suffering from diabetes and taking insulin or oral hypoglycemic agents suffer severe hypoglycemia if the medications are not appropriately adjusted before initiating this diet. The ketogenic diet is contraindicated in patients with pancreatitis, liver failure, disorders of fat metabolism, primary carnitine deficiency, carnitine palmitoyltransferase deficiency, carnitine translocase deficiency, porphyrias, or pyruvate kinase deficiency.
Weight loss is the primary reason patients use the ketogenic diet. Previous research shows good evidence of a faster weight loss when patients go on a ketogenic or very low carbohydrate diet compared to participants on a more traditional low-fat diet, or even a Mediterranean diet. However, that difference in weight loss seems to disappear over time.
A ketogenic diet may be an option for some people who have had difficulty losing weight with other methods. The exact ratio of fat, carbohydrate, and protein that is needed to achieve health benefits will vary among individuals due to their genetic makeup and body composition. Therefore, if one chooses to start a ketogenic diet, it is recommended to consult with one’s physician and a dietitian to closely monitor any biochemical changes after starting the regimen, and to create a meal plan that is tailored to one’s existing health conditions and to prevent nutritional deficiencies or other health complications. A dietitian may also provide guidance on reintroducing carbohydrates once weight loss is achieved.
A ketogenic diet could be an interesting alternative to treat certain conditions and may accelerate weight loss. But it is hard to follow, and it can be heavy on red meat and other fatties, processed, and salty foods that are notoriously unhealthy. We also do not know much about its long-term effects, probably because it’s so hard to stick with that people can’t eat this way for a long time. It is also important to remember that “yo-yo diets” that lead to rapid weight loss fluctuation are associated with increased mortality. Instead of engaging in the next popular diet that would last only a few weeks to months (for most people that includes a ketogenic diet), try to embrace change that is sustainable over the long term. A balanced, unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and lots of water seems to have the best evidence for a long, healthier, vibrant life.