UrbanUpdate

One of the more popular diet trends of the last couple of years has been the ketogenic diet. Usually just shortened to the “keto” diet, it was found to be one of the most popular diets among Americans in surveys taken in 2020 and 2021. The basics aren’t hard to follow: It’s a strict diet that’s high in fat. Protein is allowed, but only in moderate amounts. What you’re really cutting out in any keto diet is carbohydrates. Breads, fruits, even some vegetables: Any food source that contains carbs is on the chopping block, since the daily total intake of carbs is supposed to hover around 50 grams, max. To put that in perspective, that’s the equivalent of eating three slices of bread per day, or one cup of rice.

“For most people, this is a big change in how they might normally be eating,” says registered dietitian and certified diabetes educator Amy Kimberlain.

Many people who go on the keto diet will lose some weight over the short term. But the diet’s long-term health effects are still being worked out. For that reason, many dietitians tend to steer people away from keto. Earlier this year, a panel of experts even ranked keto as the worst diet among a group of 40. This prompts the inevitable question: Should you even do keto?

Bust Out the Bacon

Carbohydrates are a macronutrient that helps our bodies perform, especially because they’re a main source of glucose. Otherwise known as blood sugar, glucose is the fuel that powers our cells and gives us energy. That’s what your body burns to help you finish that run or hit the weights at the gym.

In the absence of carbs, the body has to turn to other sources of fuel. That’s what keto is supposed to stimulate. When there isn’t enough glucose to burn, the liver goes to work. It takes fatty acids in the body and breaks them down into ketone bodies (hence the diet’s name), which now become the body’s main source of fuel. Ketone bodies can provide energy for the heart, the kidney, and even the brain, as well as other muscles.

That’s why the keto diet emphasizes eating more fatty foods and fewer and fewer carbs: Ketones are now the energy source, instead of glucose. Fish, low-carb vegetables like broccoli and spinach, avocados, eggs, and plain Greek yogurt are just some of the keto-friendly foods you can keep eating. Coffee is allowed, as long as it’s unsweetened. So is bacon. And you can still eat poultry, too, although consuming too much protein is to be avoided, since the amino acids contained in protein can be converted to glucose.

Beware the Keto Flu

In the first few days of going on the keto diet, you’re bound to experience some flu-like symptoms. An upset stomach or headaches are fairly common, since your body has yet to reach full “ketosis”: the state of relying on ketones for fuel.

But cutting back on carbs, vilified as they are, might not be the answer. Essential vitamins—A, C, and K—are being lost if you’re not eating enough carbohydrates, and Kimberlain says that some of the long-term health effects of the keto diet can be kidney stones and liver disease. (You’re asking your liver to do a lot more, which is one of the reasons the diet is not recommended for people with any type of liver condition.)

Where the keto diet might be helpful is for people with epilepsy. Since the 1920s, ketogenic eating has been used as a treatment for epileptic seizures. According to the Cleveland Clinic, doctors think there’s something that lowers the excitability of the brain when someone’s eating lots of fat but very little sugar.

Sometimes, Simple Is Best

When it comes to producing short-term weight loss, the keto diet is ranked fairly high. But its restrictive nature makes it difficult to follow, its emphasis on fat makes dietitians like Kimberlain quite skeptical, and it lacks good evidence of its effects over extended periods of time, something that can’t be said for other diets.

“There is a lot of research showing that diets high in saturated fat may in fact increase the risk for heart disease, along with other health conditions,” she says. “Long-term cardiovascular health has not been studied for those following a keto diet.”

Bear in mind, too, that the metabolic rates of people differ. Everyone is going to lose weight differently: Your rate of producing ketones isn’t going to be the same as someone else’s. And keeping on with a pattern of eating that cuts out many of the foods we’re so used to eating is difficult to sustain. “What’s been seen,” Kimberlain says, “is that many individuals do in fact gain the weight back.”

The important thing about any diet is that it’s one that works for you—but oftentimes it's simple rules, not restrictive dogma, that are the best guide when it comes to figuring out what you should be eating every day.

More Great Wellness Stories From GQ

The Only 6 Exercises You Need to Get a Six-Pack

You Should Be Doing Hamstring Stretches Every Day—Here’s Why (and 7 To Try)

The Many Stealthy Ways Creatine Boosts Your Health

Flexibility Is a Key to Longevity. Here’s How to Improve Yours, According to Experts

How to Actually Build Muscle When You Work Out

Not a subscriber? Join GQ to receive full access to GQ.com.

Related Stories for GQFoodHealth