What Is the Keto Diet? Here's Everything You Need to Know

Lately, everyone is talking about going keto — Kourtney Kardashian, for one, can't get enough of the high-fat, low-carb diet. But what exactly does it entail? And can a diet that high in fat actually be healthy? The answer, it turns out, is more complicated than you think.

What is the ketogenic diet?

Unlike most diets, keto puts an emphasis on eating more fat than anything else. Of course, that means healthy fat — on a keto plan, your meals are going to be jam-packed with avocados, fish and seafood, eggs, nuts, and high-fat dairy.

"The ketogenic diet is a way of eating that's very high in fat (around 80 percent), moderate protein (around 15 percent), and low-carb (around 5 percent)," says Toronto-based nutritionist Abby Langer, RD. "When a person eats this way, it puts them into a state of ketosis, which means that they're burning fat instead of carbs for energy."

How does ketosis work?

According to Langer, it's all about the low carb intake. Because carbohydrates are the body's primary energy source, when those levels drop, it has to turn to fat instead.

"Fat is broken down into ketones, which are a byproduct of fat metabolism. The body then uses these ketones for fuel," she says.

Are there any drawbacks?

If you can stick with the high-fat, low-carb lifestyle, research indicates you may see benefits like weight loss and a reduced risk of heart disease and Type 2 diabetes. There's also some early evidence to suggest that a ketogenic diet could be an effective form of therapy for some cancer patients (because cancer cells require carbs to survive), as well as those with neurological disorders, from persistent headaches to more serious conditions like Parkinson's and Alzheimer's.

That said, the diet is incredibly restrictive. "It can be really challenging to sustain for the long-term. Also, eating 80 percent fat can tempt people to consume a lot of saturated fat," Langer says. "Although there are conflicting reports on this, saturated fats haven't been vindicated in terms of health. Eating a diet full of bacon and cheese really isn't recommended."

The other issue? You're not left with a whole lot of options to get by on.

"It's also limited in terms of variety. Followers cut out most fruit, starchy vegetables, legumes, and grains — all healthy foods that contain vitamins and minerals," Langer says. "If you're a plant-based eater, you're going to be eating a ton of nuts for protein."

Ready to give keto a try?

If you want to go keto, there's really only one thing to focus on: making sure you're getting your fat from quality sources. (That means seriously limiting your bacon and cheese consumption — sorry!)

"Make sure to get most of your fat from healthy sources, like salmon, avocados, and nuts. And take a multivitamin," Langer says. "Remember that keto isn't for everyone, and of course ask your doctor before you start — especially if you're diabetic or have other health issues. For some people, it's sustainable in the long-term. But if you live to eat versus eat to live, maybe not."