Is Keto Cycling Healthy? Here's What To Know About the Controversial Diet

Following a keto diet can be challenging, so taking a break for a little while can be tempting. Some supporters of keto cycling, in which you have days when you eat more carbohydrates than others, hold it up as a healthier option that helps you stick to keto longer.

But not everyone agrees. Here's what both sides had to say.

What Is the Keto Diet?

Short for "ketogenic," the keto diet is an extremely low-carbohydrate eating plan that sends the body into ketosis. Ketosis is a state in which your body burns fat for energy rather than glucose (sugars) derived from carbohydrates.

People on a ketogenic diet consume 50 grams or fewer of carbohydrates per day and instead, eat higher-than-normal amounts of fat and protein. And while they often lose weight quickly, health experts say the diet isn't sustainable—and often isn't healthy—to follow for long periods.

That's where keto cycling comes in: Touted as a less restrictive, more sustainable way to get the benefits of a ketogenic lifestyle, keto cycling involves following a ketogenic diet for a few days in a row, then taking a break and eating high (or at least average) levels of carbohydrates for a day.

In other words, it's the best of both worlds, right?

Well, as with most things, it's not quite that simple. Health checked in with two nutritionists—each with a different stance on the keto diet in general—to find out what they think about this on-again, off-again approach.

Here's what you should know before giving it a try.

What Is Keto Cycling?

Because keto cycling isn't a branded or trademarked term, there are no exact guidelines for you to follow. Some websites describe following a strict keto diet for six days a week followed by one "cheat day" or "high-carb day." Others encourage switching it up more frequently.

Josh Axe, DNM, said his preferred method of keto cycling is a two-day-on, one-day-off pattern. Axe is a big proponent of the keto diet and sells keto-related supplements on ancientnutrition.com.

But because the diet is difficult to follow long-term, Axe believed you limit it to 30 to 90 days.

"After that, it's a good idea to transition into another diet that's going to be easier to maintain, and maybe that's keto cycling," said Axe. Axe's wife tried keto cycling after doing a straight keto diet for 30 days.

"She started eating like that, two keto days and one carb day, and she noticed results probably just as good as doing the full-on keto," said Axe. "Her hormones really balanced out, she lost about 10 pounds, and we found she was able to do this long-term rather than crashing and burning the way people sometimes do on long-term diets."

As of 2022, there wasn't a lot of research looking at keto cycling's effect on adherence to a keto diet, but there was some indication that keto cycling could be as effective as a general weight-reduction eating plan.

A small study of 25 young people indicated keto cycling was as effective as a calorie-restricted diet for weight loss but may have had a negative impact on lean muscle mass. However, more research needs to be done on the eating pattern in the population as a whole.

Carb Cycling vs. Keto Cycling

Axe described keto cycling as "the keto diet meets carb cycling." So what's the difference between the two terms?

Carb cycling is a more general term used when a person cuts back on carbs for a few days followed by a high- or moderate-carb day but does not restrict so much that the body has to switch to burning fat for fuel.

"The ratios are slightly different," said Axe. "Carb cycling tends to be more high-protein, moderate-fat, and you're not really ever getting into ketosis. Keto cycling is higher-fat, higher-protein, and lower-carb than what you'd eat if you were carb cycling."

Axe added that in both carb cycling and keto cycling, people might choose to match their carb days with high-intensity workout days.

During keto cycling, the body goes in and out of ketosis depending on what fuel—fat or carbohydrates—is available for burning.

"Our hunter-gatherer ancestors weren't concerned with carb cycling," explained Axe. "But when you think about it, sometimes they were eating quite a few carbs, and sometimes they were eating fat because of the natural fluctuation in food sources."

Keto Cycling Benefits

Some proponents of keto cycling say that an on-again-off-again plan can help prevent the side effects of a full-on keto diet.

Theoretically, fatigue, nausea, diarrhea, and other "keto flu" symptoms may be lessened if people aren't in ketosis for so many days at once. There's also some concern that carbohydrate restriction over a long period may negatively affect hormones, cholesterol levels, or even people's moods.

Again, theoretically, you might avoid these problems with regular carb-replenishment days.

Because there are no published studies on keto cycling versus a regular ketogenic diet, however, no one can definitively say what the health benefits are of one over the other.

But one thing is for sure, said Axe: Mentally, keto cycling can be much easier to stick with in the long run, and it allows for more variety in the diet—something most health experts would agree is a good thing for physical health.

Axe generally recommended keto cycling as a way you could continue the ketogenic diet after an initial 30- to 90-day period of everyday carb restriction.

"But the truth is," added Axe, "somebody can just do keto cycling and can still really see results, even without doing full-on keto."

Keto Cycling Negatives

Kristen Kizer, RD, a dietitian at Pura Vida Behavioral Nutrition, advised her clients to avoid the keto diet. Kizer said it's unbalanced and restricts too many essential food groups. And while people lose weight, they almost always gain it back once they add carbs to their diet.

But that doesn't mean Kizer thinks keto cycling is any better.

Promotion of Unsafe Eating Patterns

The concern is that the keto diet can promote disordered eating and that keto cycling especially can lead to binge behaviors.

"A lot of people will think, 'All I need to do is be very low-carb for five or six days, then on my cheat days, I can eat as many carbohydrates as I want,'" explained Kizer. "It definitely is not supposed to work that way."

Weight Fluctuations

Keto cycling is also likely to make people's weight fluctuate, especially if they are coming out of several weeks or months of full-on carb restriction.

"It doesn't establish a healthy relationship with food, and it can mentally throw people off if they regain all the weight they just lost," Kizer said.

Quick-Changing, Irregular Metabolism

Kizer also pointed out that ketosis is an altered metabolic state, and, unlike Axe, worried that it's unhealthy to force the body in and out of it regularly.

"People can fall in and out of ketosis, and they won't really know where they are unless they're monitoring their ketones," said Kizer. "You can't just take a break for a day and then pick up where you left off after eating pancakes and waffles."

Kizer preferred people to follow a full-on ketogenic diet rather than keto cycling.

"Again, I'd really prefer they do neither," Kizer added, "but I just feel there's a lot more room for error when you start talking about cycling your carbs."

What To Eat When You're Keto Cycling

If there's one thing that Axe and Kizer agree on, it's that there are healthy and unhealthy ways to include carbs into your diet.

Paying attention to the carbs you eat on carb days is important. Axe suggested getting 30% to 40% of your food intake on these days from healthy starches and carbohydrates versus just 5% to 10% on keto days.

Some of Axe's favorite foods to recommend on carb days include:

• Açai bowls
• Berry smoothies with protein powder
• Sweet potato fries alongside a grass-fed burger with a gluten-free bun
• Pizza with cauliflower crust topped with chicken and buffalo mozzarella cheese
• Dark chocolate
  

Kizer said that regardless of carb cycling, ketosis, or any other diet people may try, it's always wise to choose carbohydrates that are as whole and unprocessed as possible like:

• Whole fruit
• Brown rice
• Potatoes
• Beans
• Corn
• Whole grains (e.g., quinoa, amaranth, and farro)

"I try to have my clients focus on food being as less processed as possible and avoid things like white rice, white bread, and sugary cereals," added Kizer.

Of note, the results of keto cycling can vary if you go out of ketosis too quickly or to a great extent. If keto cycling is unsustainable, or if you plan to try keto cycling, consult a healthcare provider for weight management guidance.

A Quick Review

It can be hard to follow a keto diet because you are allowed very few foods containing carbohydrates. Some people cope with the challenge by keto cycling, i.e., having some days off in which they eat more carbohydrates before returning to a complete keto plan.

Proponents of keto cycling say it makes the eating pattern more sustainable, while others say it can lead to disordered eating. Either way, there is no clear rule about how many days you take off and how many carbs you should eat on those days.

Trial and error might be the best way to make keto cycling work for you. And, if you cycle, experts recommended choosing healthy carbohydrates rather than unhealthy ones.