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The ketogenic diet is crazy popular right now. For a lot of people, it seems like a manageable change in eating style that can help them look and feel better. After all, how hard can a diet be to sustain if you’re allowed to eat butter, cheese, bacon, and as much avocado as your heart desires?!
But there are *so many* things people get wrong about the keto diet—not just in terms of which foods to eat, but also how much to eat, the most effective ways to implement the diet, and what the real benefits (and risks) are. And keto experts are getting tired of it. Here’s what they want you to know.
1. It’s not just about eating fat.
Most people hear “keto” and immediately think “fat.” (If you’re not familiar, keto essentially is a high-fat, very low-carb diet that puts your body into a state called ketosis, where it uses fat for fuel instead of carbs. Here’s more about how the keto diet works.)
But that’s not the whole story. “You can eat more fat, but the type of fat you eat does matter,” says Molly Devine, R.D., a registered dietitian and advisor to KetoLogic.
“We really are what we eat and if the animals providing your dietary fat are eating poor-quality food, guess what? Their fat is pretty poor quality, too,” she says. “Grass-fed and free-range animals produce foods with higher nutritional quality, which is free of added hormones and other toxins that can lead to disease and metabolic dysfunction. Including a wide variety of fats, both from animals and plants will create a more balanced and interesting diet.”
2. It’s also not just about eating animal products.
Butter. Bacon. Cheese. *Insert heart eyes emoji here.* These are all things you can eat on keto, maybe in larger amounts than if you were following another type of diet. But you don’t have to eat them.
“This assumption that ketogenic diets require animal products is problematic because it sets up a false dichotomy between keto and vegetarianism,” says Catherine Metzgar, Ph.D., R.D., a registered dietitian and nutritional biochemistry expert who works with Virta Health. “It is certainly possible to eat a vegetarian or lactose-free ketogenic diet.” In fact, plenty of her clients do it, she says—it’s just a matter of some careful planning. (See: Is It Possible to Follow a Vegetarian or Vegan Keto Diet?)
3. Nope, it’s not a high-protein diet.
“This isn’t a low-carb, high-protein way of eating,” Devine points out. Because it’s so common these days to emphasize protein intake, a lot of keto dieters accidentally OD on the stuff, which takes you out of ketosis. (Here, a nutritionist explains exactly why the added protein trend has gotten out of control.) “FAT needs to be your primary fuel source and that means finding pure-fat sources that don’t include protein. Your body will convert excess protein into glucose for fuel and this will spike insulin, preventing ketosis.”
4. Um, YES, you should be eating fruits and veggies.
“A lot of people also think that they cannot eat fruits or vegetables on a ketogenic diet,” says Pegah Jalali, R.D., a registered dietitian at Middleberg Nutrition. If you take one thing away from this article, let it be this: You definitely still need to eat fruits and vegetables, no matter what kind of diet you’re on.
Also, there are quite a few fruits and veggies that are keto-friendly. “You can eat many low-carbohydrate vegetables like zucchini, cauliflower, mushrooms, cucumbers and more,” says Jalali. “Fruits are a little harder to fit into a ketogenic diet, but many of my patients enjoy raspberries and other low-carbohydrate fruits in portioned amounts.” (Here’s a keto meal plan for beginners that spells everything out.)
5. Nutrient deficiencies and other health issues are a concern.
There are some common health issues that occur on keto, most of which can be avoided through careful planning.
“The ketogenic diet has many side effects and this is why it’s important that individuals work with a medical professional like an M.D. or R.D. who has experience with the diet,” says Jalali. “Some common side effects are constipation, elevated cholesterol, kidney stones, vitamin deficiencies including zinc, copper, selenium, and vitamin D.” (Related: Is The Keto Diet Bad for You?)
Mineral and electrolyte deficiencies are also quite common in the early stages of keto. “Many people become dehydrated and deficient in electrolytes as the body sheds large amounts of water from carb restriction,” explains Devine. “Sodium, potassium, and magnesium are the big three that I supplement with at this stage.” (These hydration supplements can be added right to your water.)
Cholesterol levels are also sometimes affected by the keto diet. “It’s important to ask your physician to check a fasting lipid panel before starting a ketogenic diet and three months later if you plan to continue,” says Julie Stefanski, R.D., a registered dietitian and specialist in the ketogenic diet.
“In a recent study which used a ketogenic meal plan for a year, researchers saw a rise in LDL (bad cholesterol), but the change was felt to be minimal,” she says. “On the upside, they also documented a desirable increase in HDL (good cholesterol) and a decrease in triglyceride levels and inflammatory indicators, both of which are risk factors for heart disease.” Still, it’s a good idea to involve a dietitian or doctor in your keto diet plans so you can monitor the health impact.
Of course, this isn’t an exhaustive list of everything that can go wrong on keto, but as you can see, there are some legitimate concerns here. Which leads us to…
6. It’s traditionally a therapeutic diet—and that has implications.
The keto diet can improve your health. But it’s also not a dietary choice to make on a whim—and it’s *not* just a slightly-more-intense version of other low-carb diets.
“Although ketogenic diets have recently come into vogue, it’s incorrect to label this as an offshoot of Atkins,” says Metzgar. “Ketogenic diets have been therapeutically used for over a century to treat refractory epilepsy in children. In addition, clinical trials of ketogenic diets demonstrate that they can result in profound health improvements and medication reductions for people living with type 2 diabetes. While there are many benefits to a ketogenic diet, it does change the body’s metabolism. People should consider it more like a medical choice they plan to commit to rather than just something to ‘try.'” (And for that matter, you need to know how to safely come off the keto diet.)
7. Cheat meals on keto aren’t a thing.
“To experience the full benefits of a ketogenic diet, consistency matters,” says Metzgar. That means not veering off course every week to indulge in a “cheat” meal. Each time you eat carbs, you take yourself out of ketosis, and you’ll need to start all over again to get back into it.
“Forgoing the staple of a modern diet, carbohydrates, requires effort, sacrifice, and in many cases navigating social situations,” she adds. “Without a strong motivation or medical need, it can be hard for an individual to commit long-term to a ketogenic diet.”
8. Keto doesn’t guarantee weight loss.
“There’s a misconception that keto automatically leads to weight loss,” Stefanski says. In reality, weight loss is not the point of the keto diet. It’s possible to lose weight on keto, but it’s also possible to gain it, she points out. (However, one Shape editor tried keto and lost more weight than she expected.)
“I really wish that people considering keto as an option for weight loss would meet with a licensed nutritionist first to assess the real reason for excess weight gain,” adds Stefanski. “If the cause of a person’s obesity is stress eating or not enough exercise, keto isn’t going to fix those issues. When a keto dieter gets bored, they’ll be right back where they started.”
While keto is definitely a viable option for many people, it may also be worth it to explore other approaches before making a decision about which eating style to pursue, such as mindful eating, IIFYM or macro counting, or intuitive eating.