If you’re looking to get a jump start on your health and fitness goals this year, you may be thinking about trying the ketogenic diet. Maybe you’ve heard the phrase before — it’s a huge diet buzzword — but aren’t sure what it means. Here’s a primer: The ketogenic diet is an eating plan that drives your body into ketosis, a state where the body uses fat as a primary fuel source (instead of carbohydrates), says Stacey Mattinson, RDN, who is based in Austin, Texas.
When you’re eating the foods that get you there (more on that in a minute), your body can enter a state of ketosis in one to three days, she adds. During the diet, the majority of calories you consume come from fat, with a little protein and very little carbohydrates. Ketosis also happens if you eat a very low-calorie diet — think doctor-supervised, medically recommended diets of 600 to 800 total calories per day.
Benefits and Risks of the Diet That Beginners Need to Know
Before you dive in, it’s key to know the possible benefits and risks of keto.
Research backs up undertaking a ketogenic diet in three circumstances: to aid treatment of epilepsy, to help manage type 2 diabetes, and to support weight loss, says Mattinson, and the last two purposes still need more studies. “In terms of diabetes, there is some promising research showing that the ketogenic diet may improve glycemic control. It may cause a reduction in A1C — a key test for diabetes that measures a person’s average blood sugar control over two to three months — something that may help you reduce medication use,” she says. But for people with diabetes, one big concern is you’re eating a lot of fat on keto, and that fat may be saturated, which is unhealthy when eaten in excess. (The much higher total fat intake is also a challenge among keto beginners.)
Because people with type 2 diabetes are at an increased risk for cardiovascular disease, there’s a specific concern that the saturated fat in the diet may drive up LDL, or “bad,” cholesterol levels, and further increase the odds of heart problems. If you have type 2 diabetes, talk to your doctor before attempting a ketogenic diet. She may recommend a different weight loss diet for you, like a reduced-calorie diet, to manage diabetes. Those with epilepsy should also consult their doctor before using this as part of their treatment plan.
The keto diet may also help improve short- and long-term cognition among people who are living with Alzheimer’s disease and are experiencing mild cognitive impairment, according to a systematic review of randomized controlled trials that was published in Advances in Nutrition in June 2020.
Researchers caution that further research is needed to confirm these findings and prove a cause-and-effect relationship between keto and preventing dementia.
One downside to the ketogenic diet for weight loss is that it’s difficult to maintain. “Studies show that weight loss results from being on a low-carb diet for more than 12 months tend to be the same as being on a normal, healthy diet,” says Mattinson. While you may be eating more satiating fats (like peanut butter, regular butter, or avocado), you’re also way more limited in what’s allowed on the diet, which can make everyday situations, like eating dinner with family or going out with friends, far more difficult. Because people often find it tough to sustain, it’s easy to rely on it as a short-term diet rather than a long-term lifestyle.
Another potential downside to the keto diet: the keto flu. One study, published in March 2020 in Frontiers in Nutrition, found that across 43 different online forums for people following a keto diet, about a third of commenters reported experiencing this short-term keto side effect. In the first few days after you begin your keto diet plan, you may experience headaches, muscle cramps, fatigue, nausea, constipation, and other flu-like symptoms, according to Harvard Health Publishing.
These symptoms usually resolve within a few days to a few weeks, and you can help to counter them by drinking plenty of fluids with electrolytes, according to an article published June 2020 in StatPearls.
Before starting, ask yourself what is really realistic for you, Mattinson suggests. Then get your doctor’s okay. You may also work with a local registered dietitian nutritionist to limit potential nutrient deficiencies and talk about vitamin supplementation, as you won’t be eating whole grains, dairy, or fruit, and will eliminate many veggies. “A diet that eliminates entire food groups is a red flag to me. This isn’t something to take lightly or dive into headfirst with no medical supervision,” she says.
What to Keep in Mind When Creating Your Ketogenic Meal Plan
If you’ve decided to move forward in trying the keto diet, you will want to stick to the parameters of the eating plan. Roughly 60 to 80 percent of your calories will come from fats. That means you’ll eat meats, fats, and oils, and a very limited amount of nonstarchy vegetables, she says. (This is different from a traditional low-carb diet, as even fewer carbs are allowed on the keto diet.)
The remaining calories in the keto diet come from protein — about 1 gram (g) per kilogram of body weight, so a 140-pound woman would need about 64 g of protein total. As for carbs: “Every body is different, but most people maintain ketosis with between 20 and 50 g of net carbs per day,” says Mattinson. Total carbohydrates minus fiber equals net carbs, she explains.
One thing to remember: “It’s easy to get ‘kicked out’ of ketosis,” says Mattinson. Meaning, if you eat something as small as a serving of blueberries, your body could revert to burning carbohydrates for fuel rather than fat.
A Complete Food Guide to Follow
Wondering what fits into a keto diet — and what doesn’t? “It’s so important to know what foods you’ll be eating before you start, and how to incorporate more fats into your diet,” says Kristen Mancinelli, RD, author of The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, who is based in New York City. We asked her for some guidelines.
Protein
Liberally Ketogenic diets aren’t high in protein (they focus on fat) so these should all be consumed in moderation.
- Grass-fed beef
- Fish, especially fatty fish, like salmon
- Dark meat chicken
Occasionally
- Bacon
- Low-fat proteins, like skinless chicken breast and shrimp. These are great to include in your keto diet, but add a sauce on top for some fat rather than eating them plain.
Never
- Cold cuts with added sugar (read the label!)
- Meat that has been marinated in sugary sauces
- Fish or chicken nuggets
Oil and Fat
Liberally
- Avocado oil
- Olive oil
- Coconut oil
- Butter
- Heavy cream
Occasionally Limit your consumption of these oils, which should be easy to do if you’re avoiding packaged foods, where they’re often found.
- Sunflower oil
- Safflower oil
- Corn oil
Never
- Margarine
- Artificial trans fats
Common Questions & Answers
What fruit can I eat on keto?Fruit is nature’s candy, and you’ll be glad to hear certain types are okay on the keto diet when eaten in moderation. Fruits you can eat on keto include avocados, blackberries, raspberries, and lemons. The trick is aiming for a low amount of net carbs, which you can calculate by subtracting fiber from total carbs.What fast food can I eat on a keto diet?What do I eat for breakfast on the keto diet?How do I get started on the keto diet?What can I drink on the keto diet?
Fruits and Veggies
Liberally
- Avocado
- Leafy greens, like spinach and arugula
- Celery
- Asparagus
Occasionally These are great choices, but you’ll need to count the carbs.
- Leeks
- Spaghetti squash
- Eggplant
Never
- Potatoes
- Corn
- Raisins
Nuts and Seeds
Liberally
- Walnuts
- Almonds
- Flaxseed and chia seeds
Occasionally
- Unsweetened nut butters (almond or peanut butter)
- Cashews
- Pistachios
Never
- Trail mixes with dried fruit
- Sweetened nut or seed butters
- Chocolate-covered nuts
Dairy Products
Liberally
- Cheddar cheese
- Blue cheese
- Feta cheese
Occasionally
- Full-fat cottage cheese
- Full-fat plain Greek yogurt
- Full-fat ricotta cheese
Never
- Milk
- Sweetened nonfat yogurt
- Ice cream
Sweeteners
Liberally None; always practice moderation with sweeteners.
Occasionally
- Stevia
- Erythritol
- Xylitol
Never
- Agave
- Honey
- Maple syrup
- White and brown sugars
Condiments and Sauces
Liberally
- Guacamole
- Lemon butter sauce
- Mayonnaise (ensure there’s no sugar added)
Occasionally
- Raw garlic
- Tomato sauce (look for those with no added sugar)
- Balsamic vinegar
Never
- Barbecue sauce
- Ketchup
- Honey mustard
Drinks
Liberally
- Water
- Almond milk
- Bone broth
- Plain tea
Occasionally
- Black coffee (watch caffeine consumption)
- Unsweetened carbonated water (limit only if bubbles make you bloated)
- Diet soda
- Zero-calorie drinks
Never
- Soda
- Fruit juice
- Lemonade
Herbs and Spices
Liberally All herbs and spices fit in a keto diet, but if you’re using large amounts, Mancinelli recommends counting the carbs.
- Salt (salt foods to taste)
- Pepper
- Thyme, oregano, paprika, and cayenne
Occasionally These are good choices, but do contain some carbs.
- Ground ginger
- Garlic powder
- Onion powder
Never
- No herbs and spices are off-limits; they’re generally okay to use in small amounts to add flavor to foods.
Supplements
Consider taking
- Fiber
- Multivitamin
Optional These help you produce ketones more quickly; Mancinelli says she has no recommendation about taking or avoiding them.
- MCT oil
- Exogenous ketones
A Detailed Ketogenic Diet Food List to Follow
The following are some of the best foods to eat on the keto diet, along with their serving sizes and an explanation of why they’re good for people who follow this eating approach.
Avocado Oil
Per 1 tablespoon (tbsp) serving 124 calories, 0g net carbs, 0g protein, 14g fat
Benefits This is a good source of heart-healthy monounsaturated fatty acids.
Canola Oil
Per 1 tbsp serving 124 calories, 0g net carbs, 0g protein, 14g fatBenefits Research has shown that consumption of canola oil can reduce total and bad cholesterol.
Coconut Oil
Per 1 tbsp serving 116 calories, 0g net carbs, 0g protein, 14g fat
Benefits While high in saturated fat, coconut oil may increase “good” HDL cholesterol levels.
MCT Oil
Per 1 tbsp serving 115 calories, 0g net carbs, 0g protein, 14g fatBenefits Derived from coconut, MCT stands for medium chain triglycerides. Limited research suggests MCT oil may aid in weight loss and help promote ketosis.
Butter
Per 1 tbsp serving 100 calories, 0g net carbs, 0g protein, 11g fatBenefits Though the serving provides 11 g of saturated fat, research has found that butter isn’t a major factor in increasing risk of chronic conditions like heart disease or diabetes.
Cheddar Cheese
Per 1 slice serving 113 calories, 0g net carbs, 7g protein, 9g fatBenefits Cheese is allowed as you please, but cheddar is a good example of its nutrition stats. One study found that cheese eaters had a 12 percent lower risk of type 2 diabetes.
Heavy Cream
Per 1 tbsp serving 52 calories, 0g net carbs, 0g protein, 5g fat
Benefits This is an easy way to add calories and fat into a ketogenic diet.
Bacon
Per 1 slice serving 43 calories, 0g net carbs, 3g protein, 3g fat
Benefits The green light on bacon may be one reason you’re up for sticking to the diet, as it can make eating occasions more enticing. Just watch the sodium content, as it can add up quickly.
Chicken Thigh
Per 1 thigh serving 318 calories, 0g net carbs, 32g protein, 20g fat
Benefits Leave the skin on here for extra fat. One thigh is a good source of selenium, zinc, and B vitamins.
Eggs
Per 1 egg serving 77 calories, 1g net carbs, 6g protein, 5g fat
Benefits Eggs contain the perfect duo of satiating protein and fat; they’re also high in the antioxidant mineral selenium.
Ground Beef
Per 3-ounce (oz) serving (measured raw) 279 calories, 0g net carbs, 12g protein, 24g fat
Benefits Ground beef (made with 70 percent lean meat and 30 percent fat) is a higher-fat choice — but that’s the point here. You’ll also get an excellent source of vitamin B12, which is necessary to keep up your energy levels.
New York Strip Steak
Per 3 oz serving 224 calories, 0g net carbs, 22g protein, 14g fat
Benefits You’ll get an impressive amount of muscle-building protein plus satiating fat in this option. It’s also rich in zinc, a mineral that promotes proper thyroid function.
Asparagus
Per 1 cup (raw) serving 27 calories, 2g net carbs, 3g protein, 0g fat
Benefits Asparagus contains bone-building calcium, plus other minerals, such as potassium and magnesium, which has been linked with blood sugar regulation.
Avocado
Per ½ avocado serving 160 calories, 2g net carbs, 2g protein, 15g fat
Benefits The creamy fruits are packed with fiber, something that you may lack on the keto diet. They also are an excellent source of immune-revving vitamin C.
Bok Choy
Per 1 cup (shredded) serving 9 calories, 1g net carbs, 1g protein, 0g fat
Benefits Chinese cabbage is a rich source of vitamins A and C, and offers some calcium and energy-boosting iron.
Cauliflower
Per 1 cup (raw) serving 25 calories, 2g net carbs, 2g protein, 0g fat
Benefits Provides more than three-quarters of your vitamin C quota in a day; with 3 g of fiber, it’s also a good source of the heart-healthy nutrient.
Celery
Per 1 cup (raw) serving 16 calories, 1g net carbs, 1g protein, 0g fat
Benefits Celery is one of the most hydrating veggies out there. These crunchy spears also contain vitamins A and K, and folate.
Cucumber
Per ½ cup (slices) serving 8 calories, 2g net carbs, 0g protein, 0g fat
Benefits Cukes are high in water, making them a hydrating choice. They’re also a surprisingly good source of vitamin K, a vitamin important for proper blood clotting and bone formation.
Green Peppers
Per 1 cup (sliced) serving 18 calories, 2g net carbs, 1g protein, 0g fat
Benefits Along with more than a day’s requirements for vitamin C, they’re also a good source of vitamin B6, which plays a role in more than 100 enzyme reactions in the body.
Lettuce
Per 1 cup (shredded) serving 5 calories, 1g net carbs, 0g protein, 0g fat
Benefits Leafy greens can add bulk to your meals for very few calories, as well as skin-strengthening vitamin A and vitamin C.
RELATED: 5 Simple Ways to Protect Your Skin
Mushrooms
Per 1 cup (raw) serving 15 calories, 1g net carbs, 2g protein, 0g fatBenefits Mushrooms are known for their potential immune-boosting properties, as one study suggested.
They’re also an excellent source of B vitamins.
Zucchini
Per 1 cup (sliced, raw) serving 18 calories, 3g net carbs, 1g protein, 0g fat
Benefits This is a great way to sneak in additional fiber, and the veggie also offers a good source of manganese, a mineral that helps form bone and aids in blood sugar control.
A 7-Day Sample Menu for the Keto Diet
Day 1
Breakfast Scrambled eggs in butter on a bed of lettuce topped with avocado
Snack Sunflower seeds
Lunch Spinach salad with grilled salmon
Snack Celery and pepper strips dipped in guacamole
Dinner Pork chop with cauliflower mash and red cabbage slaw
Day 2
Breakfast Bulletproof coffee (made with butter and coconut oil), hard-boiled eggs
Snack Macadamia nuts
Lunch Tuna salad stuffed in tomatoes
Snack Roast beef and sliced cheese roll-ups
Dinner Meatballs on zucchini noodles, topped with cream sauce
Day 3
Breakfast Cheese and veggie omelet topped with salsa
Snack Plain, full-fat Greek yogurt topped with crushed pecans
Lunch Sashimi takeout with miso soup
Snack Smoothie made with almond milk, greens, almond butter, and protein powder
Dinner Roasted chicken with asparagus and sautéed mushrooms
Day 4
Breakfast Smoothie made with almond milk, greens, almond butter, and protein powder
Snack Two hard-boiled eggs
Lunch Chicken tenders made with almond flour on a bed of greens with cucumbers and goat cheese
Snack Sliced cheese and bell pepper slices
Dinner Grilled shrimp topped with a lemon butter sauce with a side of asparagus
Day 5
Breakfast Fried eggs with bacon and a side of greens
Snack A handful of walnuts with a quarter cup of berries
Lunch Grass-fed burger in a lettuce “bun” topped with avocado and a side salad
Snack Celery sticks dipped in almond butter
Dinner Baked tofu with cauliflower rice, broccoli, and peppers, topped with a homemade peanut sauce
Day 6
Breakfast Baked eggs in avocado cups
Snack Kale chips
Lunch Poached salmon avocado rolls wrapped in seaweed (rice-free)
Snack Meat-based bar (turkey or pork)
Dinner Grilled beef kebabs with peppers and sautéed broccolini
Day 7
Breakfast Eggs scrambled with veggies, topped with salsa
Snack Dried seaweed strips and cheese
Lunch Sardine salad made with mayo in half an avocado
Snack Turkey jerky (look for no added sugars)
Dinner Broiled trout with butter, sautéed bok choy
How to Follow the Keto Diet on a Budget
Fresh, high-fat avocados and low-carb berries, not to mention nuts and other unprocessed foods, can break the bank, especially if they’re not already part of your budget. Fortunately, there are a few hacks you can follow to cut down on costs while following the keto diet. Buying frozen fruits and nuts in bulk are just two examples.
Learn More About Following Keto on a Budget
Snacks: Which Are the Best Options?
Snacking on the keto diet can be tricky, because the usual go-tos (think chips, crackers, and granola bars) are off-limits. Starchier whole foods that are usually considered healthy, such as bananas, won’t fly either because of their higher carb count.
Even if you don’t think of yourself as a snacker, you’ll want to keep keto-friendly options on hand (in your purse or backpack and in your office desk) when hunger strikes.
Some nuts, certain meats, olives, and cheese — all high-fat, low-carb eats — are approved.
Other good news: Many companies are getting into the business of the keto diet and are creating their own specialty products that take the guesswork out of macronutrient counting. Some even have tried to mimic favorite comfort foods typically high in carbs, like candy, potato chips, and even cookies.
Learn More About the Best Snacks to Eat on Keto
Learn More About Keto Diet-Friendly Convenience Foods
Keto Fast-Food and Restaurant Options Are More Available Than You May Think
Let’s face it: It’s unrealistic to think you’re going to cook every meal, every day, when you’re on the keto diet. Fortunately, a growing number of restaurants are offering healthy options that fit in a keto diet — and some have even hopped on the keto bandwagon officially.
Take Chipotle, which now offers a Keto Salad Bowl, complete with carnitas, guacamole, tomatillo red chile salsa, and cheese. And that’s just the beginning. With bunless burger options galore at fast-food chains across the United States, dining out on keto doesn’t have to be rocket science.
Still, you might want to do a little research before an upcoming road trip or a night out. Same goes if you know you’re not going to have as much time for meal prep on a certain week and know you’ll have to resort to hitting the drive-through.
When it comes to ordering, the same general keto meal-plan rules apply: Steer clear of the buns, the tortillas, the rice, and the breaded meats. When in doubt, opt for a salad with nonstarchy veggies, cheese, avocado, and a simple, olive oil–based salad dressing.
If you aren’t a salad fan, though, rest assured that you have numerous other options at your disposal.
Learn More About Ordering Fast Food on the Keto Diet
Learn More About Keto-Friendly Restaurants
10 Websites Where You Can Find Ketogenic Diet Recipes
There are plenty of keto Instagram accounts, blogs, and books you can browse for ketogenic diet recipes (we love these keto Instant-Pot recipe ideas, for example!). But browsing some of these beloved keto websites offer a good starting point when building your meal plan:
Keto-Adapted
Keto Karma
10 Great Keto Cookbooks for Low-Carb, High-Fat Recipe Inspiration
Keto: The Complete Guide to Success on the Ketogenic Diet, Including Simplified Science and No-Cook Meal Plans, by Maria Emmerich and Craig Emmerich
The Easy 5-Ingredient Ketogenic Diet Cookbook: Low-Carb, High-Fat Recipes for Busy People on the Keto Diet, by Jen Fisch
Simply Keto: A Practical Approach to Health & Weight Loss, With 100+ Easy Low-Carb Recipes, by Suzanne Ryan
The Complete Ketogenic Diet for Beginners: Your Essential Guide to Living the Keto Lifestyle, by Amy Ramos
The Keto Reset Diet: Reboot Your Metabolism in 21 Days and Burn Fat Forever, by Mark Sisson and Brad Kearns
The Ketogenic Diet: A Scientifically Proven Approach to Fast, Healthy Weight Loss, by Kristen Mancinelli
Ketogenic Diet: The Step by Step Guide for Beginners: Ketogenic Diet for Beginners: Optimal Path for Weight Loss, by Jamie Ken Moore
Ketogenic Diet Cookbook: 500 Ketogenic Diet Recipes to Cook at Home, by Emily Willis
The Keto Crock Pot Cookbook: Quick and Easy Ketogenic Crock Pot Recipes for Smart People, by Loretta Wagner