The Atkins diet may be a distant memory for a lot of us, but the thing about once-popular fads? They inevitably re-emerge. And along with the crop tops and overalls of the early 2000s, another craze making a comeback is the low-carb lifestyle—this time, in the form of the ketogenic diet. And with any trend, if you’re going to jump on board, you’ve got to know how to do it right. That’s where we come in to help you with this all-you-need-to-know guide to killing it at keto.
What Is the Keto Diet?
Although the ketogenic diet is more popular than ever now, its origins go back to 1923, when it was founded at the Mayo Clinic to treat epilepsy. Taking a high-fat and extremely low-carb approach to eating, the diet’s breakdown of macronutrients generally falls in the realm of 60-75 percent fat, 15-30 percent protein, and 5-10 percent carbohydrates.
Why go so low-carb? When the body isn’t consuming carbs, it begins to use its fat stores as fuel. The liver breaks down fat cells, forming ketones that are used as alternative sources of energy. Once your body is in this state, it’s supposed to facilitate fat loss more effectively than a higher-carbohydrate diet would—this is what you’d call being in a state of ketosis. (Here’s a good way to test whether you’re in ketosis.)
While there are parallels between the keto diet and the Atkins diet, what sets keto apart is that, unlike the latter, it doesn’t give an unlimited pass to protein consumption, since excess protein, like carbohydrates, gets converted to glucose—something we don’t want much of in order to reach ketosis faster. So, what can you eat?
What You Can Eat
Unlike most other diets, it’s not “all veggies go” on keto. There’s really no such thing as a bad vegetable, but some are higher in carbs than others, going against keto principles. Instead of starchy root veggies, stick to those that grow above ground, plus high-fiber ones. Here’s a non-exhaustive list:
- Leafy greens
- Bell peppers
Herbs and Spices
They’re perfect for adding tons of flavor to your food without relying on condiments (ahem, sugar). Go beyond the usual salt and pepper and season your meals generously with cumin and cinnamon, basil and oregano, parsley and sage, paprika and turmeric, garlic and ginger… you get the idea.
Most fruits are too high in sugar to be acceptable for the keto diet, but there are some you can enjoy in moderation. Stick to small servings and try to limit your intake to one serving a day.
- Avocados: High in fat and low in sugar, this is actually a fruit you can eat often on the keto diet.
- Berries: Strawberries, blueberries, raspberries, blackberries, but stick to a small serving size (1 cup of blueberries could have 20 grams of carbs)
- Lemons: Not that you’re actually chomping into a lemon as a snack, but just know that you can if the urge happens to strike. Or simply use it to flavor meals and beverages.
Fats and Oils
The cornerstone of the keto diet, fat is the macronutrient to really zone in on here, but make sure you’re feasting on the right fats. Recommended fats on the keto diet include:
Monounsaturated Fats (MUFAs):
- Certain oils: Avocado, walnut, olive, and flaxseed are optimal.
- Avocados: Worth a second mention.
- Olives: Pair ’em with cheese for a keto snack plate.
- Nuts and nut products: Just make sure the nuts haven’t been roasted in vegetable oil (oh, and no peanuts).
- Cow’s milk butter: It makes everything better.
- Coconut products: Oil, butter, milk, cream, and shredded coconut to name a few.
- Ghee: Cook just about anything in this delicious clarified butter.
- Lard: Yes, bacon. Need we say more?
Medium-Chain Triglycerides (MCTs):
With their ability to digest quickly and promote ketosis, MCTs are a super-popular addition on the keto diet. Coconut oil contains MCTs, but the pure stuff is usually available in supplement form as oils or powders that you can add to your coffee or drizzle onto food.
A note on polyunsaturated fats: While polyunsaturated fats are conventionally categorized as the good-for-you kind, the keto diet does warn of the inflammatory effects of omega-six polyunsaturated fats in vegetable oils and margarine. Be sure to balance them out with moderate quantities of omega-3 polyunsaturated fats, like fatty fish.
Always go full-fat.
- Cheeses: Cheddar, Swiss, cottage, gouda, ricotta… drooling yet?
- Yogurt: Full-fat, plain, and unsweetened is the way to go.
- Sour cream: To dollop on low-carb tacos or even use in keto-friendly baking.
- Heavy cream: Add a few spoonfuls to your coffee or thicken curries and soups with it.
Fat is the foremost way to keep your body in ketosis. However, protein is still a crucial part of the keto diet because it enables gluconeogenesis, a process that fuels some tissue and maintains glucose levels where ketones can’t. Include these on your plate to get your fix:
- Poultry: Turkey works, but ideally, you want fattier cuts of chicken like thighs or wings.
- Beef: Choose higher-fat cuts like steaks over lean ground beef.
- Pork: Oh, hey, pork belly low-carb tacos!
- Seafood: Especially oily fish like salmon, mackerel, sardines, and tuna.
- Eggs: No more “egg white-only” omelets. Embrace the yolk, which is where all of the fat (and tons of nutrients) lives.
- Nondairy milk: Coconut is best, but don’t rule out unsweetened almond, cashew, and hemp milk too.
- Bone broth: When you need something warm but can’t have the caramel macchiato, go for this instead.
- Some sweeteners: Sugar is totally taboo, but there are certain ingredients that are keto-approved to sweeten things up, like stevia, erythritol, and monkfruit—all in moderation.
What You Can’t Eat
- Grains: Bread, rice, pasta, and oats are all no-no’s. So are couscous, farro, barley, and bulgur. Even gluten-free grains, including quinoa, polenta, cornmeal, and millet are off the table.
- Legumes and beans: While they’re high in fiber and provide great nutrients, they’re too high in carbohydrates to suit the keto diet.
- Low-fat and processed dairy products: This is not the diet for light cream cheese or skimmed milk. In fact, milk should be used sparingly, since you don’t want to be consuming too many of those milk sugars. Stick to a splash in plain coffee rather than a full-on cappuccino.
- Starchy vegetables: Starch = carbs. Carbs = off-limits. Might as well take beets, Brussels, butternut squash, carrots, corn, parsnips, potatoes, peas, and pumpkin off your grocery list.
- High-sugar fruits: Fruit can be a refreshing palate-cleanser when you’re eating so many other richer foods, but most varieties are simply too high in sugar to support ketosis, including apples, bananas, grapes, mangos, and pears.
- Dried fruit: Even the unsweetened dried apricots, raisins, dates, and prunes have way too much natural sugar to be kosher for keto.
- Juices: It’s like drinking liquid sugar.
- Any and all sugar: Whether it’s added or naturally occurring, sugar must be pretty much eliminated. Don’t forget, added sugars even hide in condiments like ketchup, teriyaki sauce, and relish, so read ingredient labels carefully.
- Processed/packaged foods: They’re usually hotbeds of hidden sugar, trans fats, preservatives, and other very non-keto ingredients.
What’s Up For Debate
- Peanuts and peanut butter: Although peanuts are high in fat, they’re also technically legumes and higher in carbohydrates than other nuts. While some keto eaters don’t see an issue with eating them in small amounts, others take a strict stance against them.
- Soy: While tofu is a low-carb food, commercially available soy products like soymilk and soybean oil tend to be made with highly processed soybeans, and anything highly processed is forbidden on the keto diet. Vegetarians and vegans going keto could use tofu as a source of protein, but if you don’t have those restrictions, stick to meat, seafood, and eggs.
- Alcohol: Most alcoholic drinks do contain sugar, and sugar means carbohydrates. It’s probably a better idea to fill your carb quota with vegetables, which offer more fiber and nutrients. If you really need to take the edge off, stick to spirits served with unsweetened club soda.
- Condiments: It bears repeating: You’d be unpleasantly surprised by how many condiments, from barbecue sauce to Sriracha to even some types of mayonnaise, contain sugar.
7 Tips for Keto Success
- Choose the right fats.
At first glance, the keto diet can seem like an excuse to go totally nuts on all the fats. But it’s not just about quantity—consuming quality fat matters just as much, if not more. Be discerning about what types of fat you’re putting in your body, focusing foremost on monounsaturated fats and MCTs, good amounts of saturated fats, and moderate portions of polyunsaturated fats.
- Don’t go overboard on the protein.
Between the dairy, the meat, and the eggs, this high-fat diet can inadvertently turn into a high-protein one too. While protein is a key part of the equation, much of it can distract the body into producing glucose rather than going into ketosis.
- Stay organized.
Whether it’s ensuring that you’re hitting that 70-20-10-percent ratio of fats, proteins, and carbs, or having a keto-friendly meal on the table every night, take advantage of the many resources available to set yourself up for success.
- Be mindful of electrolytes and fiber.
As you cut the carbs, your body no longer stores as much water as it did when it had a greater glycogen supply. Stay hydrated with water and using both food and supplements to keep your electrolyte count high. Same goes for fiber—don’t skip out on digestion-aiding, low-carb vegetables just because you’re too busy enjoying all the cheese.
- Give your pantry a makeover.
If you’ve still got chips, cookies, bread, and soda in the house, there’s a chance temptation could win over—just a handful or two of pretzels, and you could totally derail your efforts to put your body into ketosis. There isn’t much wiggle room on the keto diet, which means there isn’t much room in your house for any food that isn’t keto-friendly. Get rid of whatever doesn’t make the cut and replace it with whatever does so that you still have plenty to eat.
- Try Intermittent Fasting.
Let’s be clear, this does not mean starving yourself. But research has shown that going for longer periods between meals can actually help to put your body in intermittent ketosis, which, in turn, has an appetite-suppressing effect. If you’re already comfortable eating the keto way, try fasting between the hours of, say, 7 p.m. and noon the next day (keep drinking water, though!) to take things one step further.
- Exercise patience.
We all may be used to instant gratification these days, but remember that you’re a human, not a robot. Your body won’t go into ketosis after just one day of eating no bread and all bacon. Typically, it takes a few weeks to adapt to the high-fat lifestyle, and the adjustment period could include bloating or the keto flu. Know that it’s normal and don’t get discouraged—you got this!
The Benefits of Going Keto
While most people know and embrace keto for its ability to burn fat with fat, it turns out there’s more a keto diet can do for you than just facilitate weight loss. Additional benefits of keto can include:
- Reduced appetite: OK, so this one goes hand-in-hand with weight loss, but the high-fat, moderate-protein nature of the diet ensures that you’re more satiated by the food you’re eating and aren’t filling up on empty carbohydrates that do nothing for your hunger.
- Better blood sugar levels: Research shows that by restricting the amount of glucose coming into the body, the keto diet has the potential to control and improve insulin and blood sugar levels, making it a promising option for those with type 2 diabetes.
- A healthier heart: Yup, you read that right. Although we’ve been lectured for years on the negative effects of too much fat on cardiovascular health, there is some recent evidence that a low-carbohydrate, high-fat diet and being in ketosis can actually have positive effects on blood lipid and cholesterol levels.
- Curbed epilepsy: Keto was founded by Dr. Russell Wilder at the Mayo Clinic as a way to treat epilepsy, and ongoing research confirms that Dr. Wilder had the right idea. The metabolic processes activated by ketosis may affect neurons in a way that, indeed, controls the frequency of epileptic seizures, all but guaranteeing the diet’s effectiveness as part of treatment for the condition.
- Prevention of other inflammatory diseases: Studies increasingly show that a ketogenic diet’s direct correlation to enhanced mitochondrial activity and reduced oxidative stress may make it effective in the prevention and/or treatment of inflammatory diseases like Alzheimer’s and Parkinson’s.
But Is the Keto Diet for You?
Going keto may be the trend of the hour, but not everyone is cut out for the diet’s intense, high-fat regimen. Achieving ketosis can come with some gnarly side effects known as keto flu, a collection of symptoms ranging from headaches, mood changes, and nausea to fatigue, insomnia, and constipation. You may even experience less-than-pleasant breath. While these are actually all part of getting to ketosis, if the symptoms are especially severe, you may decide the diet isn’t quite your cup of tea.
What’s more, a severely low-carb diet may not be optimal as a long-term lifestyle, as its restrictive nature can lead to deficiencies of vitamins and minerals that can compromise bone and gastrointestinal health. Be mindful of your body’s reactions and consult a doctor to make your transition to and from the keto diet as safely as possible.
Most importantly, remember that just because your BFF is a die-hard keto advocate doesn’t mean that you have to be if it’s not working out as well for you. If adhering to the high-fat, low-carb thing is doing wonders for your energy and health, great! But your physiology, lifestyle, and mental well-being may respond best to a diet that includes all macronutrients and the occasional frosted cupcake—and that’s totally fine too. Do what’s best for you.