An interesting report on keto diet for treatment of obesity and diabetes was recently published in JAMA, journal of the American Medical Association. The article is titled “The Ketogenic diet for obesity and diabetes – Enthusiasm outpaces evidence” by McMacken el al. The authors report that keto diet has received much attention lately mostly because low fat diets have failed to control the obesity and type 2 diabetes epidemics that plague our society. A meta-analysis of 13 studies with longer than one-year follow-up showed slightly better weight loss with keto diet when compared to high-carb, low fat diets. However, a meta-analysis of 32 studies found greater fat loss and higher energy expenditure with low fat diets when compared to keto diet. The authors further add that there are no studies evaluating the effect of keto diet on cardiovascular disease and overall mortality rate. Keto diet may improve HDL levels, but historical evidence shows no reduction in cardiovascular events with increased HDL levels. Similarly, the authors express doubt about the effect of keto diet on diabetes improvement. Long-term randomized studies comparing keto to low fat diet showed no difference in glycemic control among patients with type 2 diabetes.
The authors continue to add a number of side effects associated with keto diet including keto flu, nephrolithiasis, constipation, low fiber intake…Interestingly, the Inuit people surviving on a high fat diet in the North pole have a genetic mutation to reduce ketone body formation possibly conferring a survival advantage. The authors conclude that despite the popularity of keto diet physicians and patients need to cautiously appraise the evidence and further studies are needed to establish the safety or lack thereof of keto diet.
I fully agree with the authors that a plant-based diet based on legumes, full grains, fruits …is a healthy diet associated with decreased mortality and cardiovascular events. However, are obese and diabetic patients able to process a plant based, high carbohydrate diet to reap those health benefits. In the setting of insulin resistance and obesity, is a low carbohydrate diet like keto diet a better alternative? The best solution for obesity and type 2 diabetes is weight loss surgery like sleeve gastrectomy. Bariatric surgery changes the interaction between consumed food and gastrointestinal system resulting in neurohormonal changes that revers insulin resistance, improve appetite control… Short of a weight loss procedure like sleeve gastrectomy, asking an obese patient with a BMI of 50 to eat fruits, vegetables and grains and expect weight loss and better glycemic control is unrealistic. Obesity is a pathophysiologic state that prevents the body from normally processing carbohydrates. The alternative is to replace carbohydrates with a different form of energy like fat. Long-term fat consumption may not be healthy for you but so is obesity. Currently, there are no alternative diets to keto diet, for weight loss, in morbidly obese individuals. I fully agree with the authors that studies are needed to better understand the long-term effects of ketosis on cardiovascular mortality and events. Most importantly, I call for the complete elimination of processed carbohydrates and food from our modern diet to avoid damage to our body ability to process carbohydrate and prevent the development of insulin resistance and obesity.