Lots of people these days are interested in the ketogenic diet: It’s probably the most Googled weight-loss terms, and celebs like Kourtney Kardashian have touted its supposed benefits. However the high-fat, low-carbohydrate eating plan is not without its drawbacks.
Experts warn that the weight loss program is extremely restrictive and not sustainable, which can result in nutritional deficiencies, high cholesterol, or perhaps a serious condition called ketoacidosis. But before long-term problems occur, many people who try the diet plan report other unpleasant negative effects. These side effects actually have a name in the weight-loss world: keto flu.
Keto flu is definitely an unofficial method to describe how many people feel soon after starting a ketogenic diet, and it can include both physical and emotional symptom-like nausea, cramping, insufficient energy, and irritability, to name a few. It’s what goes on when the body?and the brain?are forced to?adapt to an abrupt?carbohydrate deficiency, says Abbey Sharp, RD, a Toronto-based nutritionist and blogger at Abbey’s Kitchen.
Proponents from the keto?diet state that these flu-like symptoms are just temporary, and that certain remedies can help reduce or get rid of them altogether. But is it really worth subjecting yourself to, even when for one small amount of time? Here’s what our experts say.
There’s no scientific definition of keto flu, but it is often referred to as flu-like symptoms that start soon after an individual cuts carbohydrates largely from their diet. (To enable “ketosis,” a sort of starvation mode where the body burns fat rather than glucose, the ketogenic diet allows for only 2% to 5% of the person’s daily calories in the future from carbohydrates.)?
“Very often, individuals don’t feel well if they are around the ketogenic diet, also it is commonly worse in the early period,” says Edward Weiss, PhD, associate professor of nutrition and dietetics at Saint Louis University. “This is one thing largely anecdotal-we don’t have studies on this-but it’s probably very real.”
A sudden stop by carbs can lead to a drop in energy levels, with some dieters reporting unusual fatigue, confusion, or confusion. “The symptoms come from your brain needing to adapt to the new energy source, while also attempting to cope with a drop in electrolyte levels while you slim down,” says Sharp. Additionally, it may cause nausea, stomach pain, cramping, and constipation, too, due to the diet’s high-fat and low-fiber makeup.
Keto dieters also sometimes report foul breath or foul-smelling sweat and urine. “The smelly factor comes from the fact that acetone, a byproduct of ketone metabolism, seeps out of your body,” says Sharp. (Ketones, a kind of acid, are byproducts of fat breaking down in your body.)
Cynthia Sass, MPH, RD, Health‘s contributing nutrition editor, says that a lot of her clients who have tried the ketogenic diet also have reported irritability and changes in mood. Even though people don’t necessarily feel hungry on the keto?diet-thanks to the high allowance for fat and moderate levels of protein-some do report serious sugar cravings.
Adopting a ketogenic diet may also hamper athletic performance, says Weiss, even though many athletes try it, thinking it’ll have the alternative effect. Inside a recent study within the Journal of Sports Medicine and Physical Fitness, Weiss and his colleagues found that after four days on the keto?diet, participants performed worse on anaerobic exercise tasks-which involve short bursts of intense activity-than those who’d recently gone on the high-carb diet.
“Our participants were right in that period of feeling terrible,” says Weiss. “They were tired, hungry, lethargic.” But he and the colleagues suspect there’s a biological reason they performed worse, too: They’d higher levels of acid within their blood, a direct result their bodies burning ketones.
“Most people find that you’ll feel better a few weeks, or up to a week, once your body adjusts,” Sharp says. “Whether or otherwise you want to place your body using that is really a personal choice.”
As for athletic performance, the participants in Weiss’s study weren’t followed long enough to see if theirs improved after more than just four days on a ketogenic diet. But other research suggests that acid levels in your body have a tendency to normalize after a couple of weeks, he says, while performance remains compromised.?
Keto?blogs and weight-loss websites recommend taking precautions-like ensuring you’re staying hydrated, getting plenty of sleep, and finding methods to manage stress-to lessen the unpleasant results of the ketogenic diet in your body. Some also recommend electrolytes, ketone supplements, or bone broth (which is full of sodium and other minerals) to replace a number of what the is missing in the?early stage?of the diet.
Certainly, prioritizing sleep, hydration, and overall healthy habits can keep you from feeling even worse, whether you’re on the keto diet or not. However the experts we spoke with agreed that avoiding ketosis altogether is a smarter method to feel good while you’re trying to lose weight, rather than putting a Band-Aid on something that could have more serious consequences down the road.?
“I don’t really recommend the keto diet in anything apart from clinical disease management settings, since it is incredibly restrictive,” says Sharp. (The?diet was originally used as a treatment for epilepsy, and scientists will also be looking into its potential benefits for people with diabetes or insulin resistance.)
Research on low-carb diets has additionally shown that while people do have a tendency to slim down faster at first, there is no long-term difference when compared with other diets of equal caloric intake. “In short, if you enjoy carbs, a balanced diet that includes them can result in just as much weight reduction,” Sharp says.
It is possible to reduce sugar and carbs-and, yes, lose weight-without experiencing these nasty symptoms, says Sharp. “While you can’t achieve ketosis with no significantly reduced-carb diet, you are able to absolutely reap many of the potential glycemic benefits of a low-carb diet-without a few of the downfalls, like keto flu-simply by choosing the right carbs,” she says.
The secret is making sure the carbs you do retain in your diet are fiber rich, like whole grains, vegetables, and fruits. So when you need to do eat those carbs, Sharp adds, pair them with some fat or protein; this slows?their glycemic impact much more, preventing?the blood-sugar spikes (and subsequent crashes) that cause cravings and crappy feelings.
Sass agrees: Inside a 2017 column, she recalled one man who became irritable and had sleep problems after adopting an ultra low-carb diet. “Those negative effects subsided after he added back fruit, pulses, whole grains, and starchy vegetables to his diet,” she wrote.