The keto diet is definitely having a moment. Although it's not yet quite clear whether the high-fat, low-carb diet will actually help you lose weight and keep the pounds off, more and more people are giving it a whirl. (The fact that it's one of the few diets that allows you to eat bacon only contributes to its popularity.)
But some people testing out the keto diet may notice one surprising side effect: breakouts.
So what's going on? First, you have to understand what the keto diet actually does to your body.
How does the ketogenic diet work?
"The ketogenic diet usually results in the body entering a different metabolic state after the third to seventh day, when the body starts producing ketones en masse in place of regular sugars," says Ross C. Radusky, MD, dermatologist at SoHo Skin & Laser Dermatology, P.C. This is a process known as ketosis.
Ketosis "is stressful on the body, at least in the beginning," he says. It can throw many of your bodily functions out of whack, causing everything from bad breath to constipation. But it also wreaks havoc on your skin.
"The skin is a temperamental beast," says Radusky. "Any change in your diet, but particularly one that turns our usual percentages of fats, carbohydrates, and proteins upside down, can be inflaming."
This is in part because keto is a high-fat diet: a 2015 study found that high-fat diets increased the production of sebum on your skin, which can increase your risk for acne. Additionally, a 2007 study looked at levels of a specific marker for inflammation, known as the C-reactive protein. It found that higher fat diets were associated with higher levels of the protein. Translation: high-fat diets may increase inflammation in the body, which has been linked to skin conditions like acne, psoriasis, and eczema.
"Systemic inflammation can lead to skin inflammation and skin dysfunction," says Joshua Zeichner, MD, director of Cosmetic & Clinical Research in Dermatology at Mount Sinai Hospital in New York City.
You also may notice your skin becoming more dehydrated, says Radusky. "The ketogenic diet helps you shed water weight, and this can shrink your skin cells, leaving you with dry, irritated skin," he adds.
How to avoid a skin freakout
OK, so it's clear the diet can mess up your skin. But here are some tips to follow to keep your skin healthy on the keto diet.
1.) Stay hydrated.
Since the keto diet can suck moisture out of your skin, up your water intake.
"I recommend patients increase their water intake to make sure their skin cells are adequately hydrated," says Dr. Radusky.
2) Limit lactose.
"Try to avoid food that are high in lactose," says Dr. Radusky. Studies have linked milk and whey-based proteins to an increase in acne.
3) Switch your cleanser.
You may need to start using an acne face wash.
"Look for a salicylic acid or benzoyl peroxide cleanser," says Dr. Zeichner. "Salicylic acid helps remove excess oil and exfoliates dead cells from the surface of the skin that block pores. Benzoyl peroxide kills acne-causing bacteria."
4) Use hydrating products
Look for products that help naturally plump up tired, dull looking skin.
"I recommend patients use a 2% hyaluronic acid primer after they wash their face and before they apply a moisturizer. Hyaluronic acid can soak up as much as 1000 times its weight in water. So for all the pounds shed in water weight on the keto diet, at least your skin is well hydrated," says Dr. Radusky.
"I also recommend a nighttime face wash that physically exfoliates the skin a few times per week. This helps clear your face of excess dirt, oils, and grime that may have accumulated throughout the day," says Radusky.
6) See a dermatologist
If you are experiencing an acne breakout you can’t get under control, talk with a board-certified dermatologist.
"She or he may recommend a product with a retinoid, a group of chemicals derived from vitamin A, that can help shrink pores, minimize sebum production, and help clear your skin," says Dr. Radusky.
7) Consider ditching the diet
"Our diet provides the building blocks for healthy function of our body in general as well as the skin. The best diet for skin health is perhaps recognized as the Mediterranean diet. It is loaded with fatty fish, colourful fruits, and green leafy vegetables," says Dr. Zeichner. "These provide free fatty acids, protein, fibre, and essential nutrients that allow the skin to function optimally."
This article originally appeared on Men’s Health US.