What Is Keto? Trendy Diet Allows for Plenty of Cheese and Fat

Updated | Ketogenics is the latest diet darling in the nutrition world, particularly because of celebrity backers like Halle Berry. In essence, the keto diet is a low-carb diet that emphasizes eating moderate amounts of protein but plentiful amounts of fat, such as avocados and cheese. The thinking: By eliminating carbohydrates, your body will instead burn stored fat through a process known as ketosis, which helps drop pounds. Although, this diet has become trendy in recent years, it was originally used in the 1920s as an epilepsy treatment.

Related: Low-carb and low-fat diets equally effective for losing weight: Study

Pegah Jalali, a doctor at the New York University Comprehensive Epilepsy Center, told NBC your body enters this state in roughly two days. In what will come as a relief to most dieters, calorie counting isn’t necessary to make the plan work.

“Mostly, I encourage my patients to eat according to their appetites,” Jalali told the outlet. “Your body can be in a ketogenic state at a range of calorie levels, and individual needs fluctuate day to day depending on activity and other factors.”

While you may not need to count calories, you do need to pay attention to how many grams of carbohydrates, protein and fats are in your foods. Studies have shown the keto diet works best when it includes fewer than 20 grams of carbs per day, making it stricter than other low-carb diets.

Roughly 60 to 80 percent of your diet should be comprised of fat, registered dietitian Stacey Mattinson told Everyday Health. Then, about 1 gram of protein per kilogram of body weight is allowed. To determine carb allowance, Mattinson explained that you need to determine the net carbs. This can be done by subtracting fiber from a food’s total carbohydrates.

“Everybody is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” Mattinson told the publication.

One thing that makes keto challenging is that even eating the wrong serving size of fruit could make your body burn carbs instead of fat.

“It’s easy to get ‘kicked out’ of ketosis,” Mattinson said. Even meats need to be consumed in moderation, and certain types are off limits completely, like breaded chicken or cold cuts. Everyday Health has a complete list of food guidelines to get you started.

Studies have shown, however, that keto does have some benefits. In 2012, a paper published in Nutrition indicated the plan could help diabetics maintain their blood sugar levels, though there is some concern about consuming excess amounts of fat. Many studies have shown the diet to be effective for losing weight.

But before attempting to tackle keto on your own, Mattinson encourages people to talk to their doctors.

“A diet that eliminates entire food groups is a red flag to me. This isn’t something to take lightly or dive into headfirst with no medical supervision,” Mattinson told Everyday Health.

This story has been updated with additional information about ketosis.