What Is the Ketogenic Diet, and Should You Do It?

Unsustainable diets tend to have one thing in common: They restrict the foods that normally keep you feeling full and recommend limp alternatives that leave you with lingering cravings. If you tend to make a beeline to the vending machine every afternoon, the fast-growing list of devout fans of the ketogenic diet say it might be the answer.

The ketogenic diet, also called the "keto" diet, is hardly new, but it's started to swell in popularity—last year it was the fifth-most searched diet on Google. "The ketogenic diet is too often viewed as simply a sugar elimination diet … but really, it is a low-carb diet [that] drastically reduces the foods that turn into sugar in the body," says Maria Emmerich, author of The 30-Day Ketogenic Cleanse and The Complete Ketogenic Diet for Beginners. In essence, pasta and bread are out, and vegetables and filling, high-fat foods are in.

"Even a less intense, modified version can help you reap the keto diet's benefits," says Josh Axe, DNM, DC, CNS. "By limiting sugars and processed grains, you lower your risk of type 2 diabetes. Eating an array of heart-healthy fats can decrease your risk of heart disease," he explains.

Curious? Here's everything you need to know about the ketogenic diet to decide whether it's right for you.

How Does It Work?

So what makes it different from every other low-carb diet out there? "Almost every cell in our bodies can use two fuel sources, glucose (sugar) and ketones (fat)," explains Emmerich. "This diet restricts carbohydrates so that it switches to using fat as its primary fuel." In other words, it encourages eating high-fat foods rather than carbohydrates to put your body in a metabolic state called ketosis.

We hear you: Isn't fat bad for you? "All of the latest, unbiased science has shown fat is not the villain it has been made out to be," says Emmerich. Instead, she suggests loading your plate with high-fat protein and nutrient-dense foods. As Axe explains, "What makes the keto diet work so well is that with little glucose from carbohydrates in our bodies, we have to burn something else—fat—for energy."

What Can You Eat?

"This lifestyle is about eating good whole foods in the right ratios of fat/protein/carbs," says Emmerich, so you're likely to feel fuller for longer. "It's so nutrient dense you need fewer calories to sustain you. Typically we just have two meals a day."

A typical day on the ketogenic diet includes a hearty breakfast at the start of the day and low-carb meal in the evening. "Breakfast can be as simple as two eggs with two strips of bacon, or just an omelet." At night, she likes to indulge in comfort food and substitute a couple of carb-heavy ingredients. "I have a lasagna that used sheets of sliced chicken breast in place of the noodles that people say is better than the traditional version."

As a rule of thumb, any high-fat, low-carbohydrate foods are encouraged in this eating plan, including the following:

  • non-starchy vegetables like leafy greens, mushrooms, and tomatoes
  • wild-caught fish, raw cheese, and grass-fed meat
  • olive oil, coconut oil, nuts, and seeds

What Changes Will You Notice?

The first few weeks are challenging, Emmerich notes. "Your body needs to learn how to use fat for fuel and this takes anywhere from a few days to a couple weeks depending on the person’s metabolic state," she says. "This is when some people get the 'keto flu.' You can have low energy, muscle aches, foggy feelings." She was able to mediate this phase by drinking plenty of water and electrolytes to help ensure her body received the nutrients it needed.

While experts are divided about the long-term effects of the ketogenic diet, Axe says it's associated with a host of benefits. "Low-carb diets can help diminish hunger and also boost weight loss through their hormonal effects," he explains in an article. "Diets high in healthy fats and protein tend to be very filling, which can help reduce overeating of empty calories, sweets, and junk foods."

Should You Try It?

The verdict is still out. While the ketogenic diet is growing in popularity, experts warn against removing entire food groups or making drastic changes to your diet without seeking advice. If you experience fatigue, bloating, mood changes, or trouble sleeping, Axe recommends talking to a professional or introducing more carbohydrates.

The take-home? If you're not ready to completely change your diet, consider incorporating some of the elements of the ketogenic diet into your lifestyle. Cut down on processed snacks, add more non-starchy vegetables to your cart, and limit carbohydrate-heavy meals like pasta and rice. Sometimes, small, sustainable diet changes can be just as mighty.

Have you tried the ketogenic diet? Tell us if you'd recommend it to friends.