The ketogenic or keto diet is a very low carbohydrate, moderate protein, high-fat diet. It has recently gained popularity as “the” way to lose weight. Proponents of this diet recommend severely restricting carbohydrates to get the body into a state of ketosis where it shifts to primarily using ketones as its main fuel through burning fat. Research shows this can be achieved by restricting dietary carbohydrate somewhere between 20 and 70 grams per day (1).
Can ketogenic diets result in weight loss? Yes.
Is ketosis required to lose weight? No.
Data has shown that hypocaloric (calories burned > calories consumed) diets with varying amounts of carbohydrates, protein, and fat can produce weight loss (2). Simply, ketosis is not a prerequisite for weight loss. More importantly, ketosis is not required to lose actual body fat. In fact, it might be a less optimal way to decrease body fat percentage. A highly controlled study published in 2016 involving overweight and obese men demonstrated that a ketogenic diet resulted in less fat loss compared to a low-fat diet (3).
Why is a ketogenic diet an attractive option for weight loss? It can be a relatively easy diet to follow by simply avoiding carbohydrate foods to help reduce calories so weight loss can be achieved. Some individuals will have a much easier time adhering to this type of diet than others; however, not all will see the same the amount of weight loss. With any type of successful weight loss diet, the key is long-term adherence. Strict diets with food rules can be attractive because they require less thinking; however, with such little flexibility, they can easily backfire. This can unfortunately result in yo-yo dieting.
In summary, very low carbohydrate diets for weight loss such as the Atkins Diet, Ideal Protein, Dukan Diet, or the Zero Carbohydrate Diet have been around for many years. A slight modification in food rules and title change has resulted in the current ketogenic diet craze. The weight loss industry will always generate a new diet trend every few years that will be touted as the best way to lose weight. The ketogenic diet is that new, popular option at the moment.