How Long Can You Stay On The Keto Diet?

There's a big reason the keto diet has exploded in popularity, to become the number one diet in the U.S. in 2020. The promise of rapid weight loss, combined with official permission to eat plenty of high-fat foods (hello, bacon!) and heaps of celebrity endorsement is a sure path to diet stardom. But all of those factors don't answer an important question: is it safe in the long run?

Despite its rapidly growing following, experts are concerned about the long-term safety of the keto diet, and warn against it. Nikola Djordjevic, M.D., of, advises "My professional recommended period of following the keto diet is about six months maximum, and that will also depend on how much the person weighed prior to starting the diet and the state of his or her overall health within those six months" (Reader's Digest).

Keto basics include getting about 75 percent of daily calories from fats, 20 percent from protein, and only five percent from carbohydrates. That radical change to normal eating habits forces the body to switch from burning glucose for fuel, to burning fat instead. Kassey Cameron, food blogger and author of The Beginner's KETO Meal Plan, explains, "During the state of ketosis your body indiscriminately burns fat for fuel. This is the fat you are eating (your foods), the fat you have stored (adipose tissue), and the fat your body naturally generates (cholesterol)" (via Parade).

Experts worry about the long-term consequences of keto

As great as that may sound, burning glucose, not fat, is our bodies' preferred way of generating energy most of the time. Studies of high-fat, low-carb diets show that there can be negative long-term consequences. One study published in April 2019 inĀ The Journal of Sports Medicine and Physical Fitness, found that athletes who followed a strict keto diet for just four days, performed worse than their high-carb peers on intense running and cycling test.

Dietitians also worry about the risk of vitamin deficiencies, digestive problems due to lack of fiber, and the long-term cardiac consequences of a diet high in saturated fats. Adding to the concern is recent research showing that people on a low-carb, high-fat diet are significantly more likely to develop atrial fibrillation (AFib), increasing their risk of stroke and heart attack (via Insider).

While following the keto diet short-term is probably fine, dietitians recommend adopting a less restrictive, more sustainable diet for the long-haul.