Celebrities keep piling aboard the bandwagon for the high-fat, ultra-low-carb diet that sends the body into a state of ketosis and starts burning fat instead of carbohydrates for fuel. The latest well-known face to check it out is former Today show host Katie Couric. Just like many of the celebs and not-so-famous who have gone before her, Couric initially suffered some “keto flu” symptoms. But also like many before her, Couric felt the effects fade after a few days. Celebs and nutritionists alike strongly recommend that you consult your doctor before embarking on the keto diet.

“If you attempt it on your own, I suggest modifying the diet to allow more carbs—especially the ones you know you can’t live without,” says Sass. “In my experience, moderation is generally the key to shedding pounds for good, optimizing health, and living a balanced, enjoyable life,” says registered dietitian Cynthia Sass.

One common version of the plan sources 75 percent of daily calories from fat, 20 percent from protein, and just 5 percent from carbohydrates. Here are just a few of the celebrities who ditching carbs for a high-fat, moderate-protein keto diet.

Katie Couric

The former Today show anchor is the latest celeb to try high-fat, low-carb keto diet. She posted on her Instagram that she’s loving it so far.

“So I’ve been doing the keto diet for a week now and I actually do feel better,” Couric said in late August, although she did mention the start was a bit rough. “The fourth or fifth day, I felt a little shaky and headachy, but I feel much better.” Those symptoms are common on the keto diet as your body adjusts to ketosis and burns fat instead of carbs for energy.

“I’m eating mostly protein and some cheese,” the 61-year-old said. “And I’m putting half-and-half in my iced coffee, and I gotta tell ya, it’s damn good.”

Gwyneth Paltrow

The actress and business mogul has posted an article on Goop that explains the diet and offers advice on how to decide if it’s right for you.

Kourtney Kardashian

Kardashian cut out most carbs including grains, beans and legumes. “I would make broccoli rice or cauliflower rice to at least feel like I was eating some carbs,” she wrote on her blog. “Then I would add protein, so I often ate grilled chicken and fish over broccoli rice, cauliflower rice or spaghetti squash. I mixed in roasted vegetables, fresh salads with homemade dressing, and smoothies made with avocados and bananas.”

The realty star admits she suffered from headaches and low energy for a couple of weeks and now allow a “treat yourself day” every week to make staying on the diet easier.

Kim Kardashian

Kourtney may have been the first Kardashian to go low-carb and high-fat, but Kim followed soon after. Big sister reportedly lost 60 pounds after the birth of her son, Saint, by following the original keto plan, the Atkins diet. She chose the Atkins 40 diet, which is designed for people who want to lose fewer than 40 pounds. On the Atkins diet you slowly reintroduce carbs, so ketosis is only part of the diet’s phase 1.

Al Roker

“The toughest part is not eating bread,” says Roker. “Last weekend I was in Paris to drop my daughter off at school for her sophomore year. I think it’s the first time in 35 years going to Paris, but I did not have any croissant or any bread.” The Today show meteorologist reports he lost 10 pounds in two weeks since starting the keto diet.

Halle Berry

“I don’t really eat pasta, anything with sugar, it’s very much meat-based,” she said. “I eat meat, I enjoy chicken and beef and a lot of vegetables.”

Healthy fats are a part of her eating all day long, but Berry emphasizes that she has abandoned sugar. “Avocado, oil, coconut oil and I use butter, but don’t have any sugar. So when your body gets trained to burn fats, it’s constantly on fat-burning mode—that’s the secret,” she said.

She cooks a lot of meals at home that follow the trendy, low-carb, moderate protein and high-fat eating plan.

Read More: 12 Celebrities Who Can’t Get Enough of the Ketogenic Diet