Bacon, cheese, butter— yup, high-fat foods are fair game on this buzzy diet. Intrigued? Read on for all the facts.

These days, you can't go anywhere without hearing about the ketogenic diet. Celebs like Kourtney Kardashian and Halle Berry have done it, Pinterest is flooded with recipe ideas for it, and #keto has been used more than 6 million times on Instagram. There’s definitely something behind all the hype. “If the diet is done right, you can lose a substantial amount of weight,” says Josh Axe, doctor of natural medicine and clinical nutritionist. But weight loss aside, is it actually a healthy way to live? Here, everything you need to know before trying it.

How it works

The premise of going keto is straightforward: Eat moderate amounts of protein, increase fat consumption, and reduce carb intake, explains Eric Westman, MD, director of the Duke Lifestyle Medical Clinic. In fact, on this plan, you should only have 20 to 50 grams of carbs per day. For reference, a small bowl of plain pasta has around 40 grams.

Here’s the science behind it: Carbohydrates that come from sugary foods and starches are converted into glucose, which our bodies naturally burn for energy. However, when you bring carb consumption down, your body is forced to find a new fuel source. So it turns to stored fat, breaking it down into molecules called ketone bodies that it uses for energy (a process called ketosis). The result? Weight loss. “You can lose a pound or two a week,” says Westman.

There are benefits beyond weight loss

Interestingly enough, doctors used the ketogenic diet as a method to treat childhood epilepsy in the 1920s. When monitored by a physician, it was found to help control seizures—especially for kids who didn’t respond to anti-seizure medications. Nowadays, experts often recommend going keto for other brain-related reasons. “The diet has been found to increase alertness and improve cognitive function,” says Westman. Though no formal studies have concluded why, he suspects this boost may come from the combination of energy-packed ketones and a reduction in sleep-inducing carbohydrates.

But is it safe?

This super-restrictive regimen is not suggested if you are pregnant or breastfeeding, or if you suffer from gallbladder or liver conditions. “In some people, it overtaxes your liver in the long term,” explains Axe. Beyond that, studies are inconclusive on how going keto affects cholesterol levels. Because of all this, it’s smart to check with a doctor before starting.

In the clear to give it a whirl? Axe suggests trying it for 90 days. After that, alternate two days of keto eating with one carb day, where 30 to 40 percent of your food intake comes from heathy sugars and starches, like sweet potatoes and berries. “Incorporating some carbs with a keto-cycling approach is much more doable and is something many people can maintain for the rest of their life,” says Axe.

What to eat

The best way to get started is to keep it simple, says Pegah Jalali, RD, a dietitian at Middleberg Nutrition in New York City. Below, a satisfying menu that keeps your carb intake low.

Breakfast: 2 scrambled eggs with 1/2 cup sautéed spinach (cooked in 1 tablespoon coconut oil).

Lunch: Arugula salad with a can of tuna (mixed with 2 tablespoons mayo), 8 toasted almonds, and lemon zest.

Dinner: 1/4 rotisserie chicken with 1 cup roasted cauliflower (cooked in 1 tablespoon olive oil), and half an avocado on the side.