A ketogenic diet gets roughly 70 to 80% of its calories from fat, 10 to 20% from protein, and just 5 to 10% from carbohydrates. For most people, that works out to about 20 to 50 grams of net carbs per day. Staying within that range shifts your body into ketosis, a metabolic state where you burn fat for fuel instead of glucose. Below is a practical breakdown of what to eat, what to limit, and what to skip entirely.
Fats and Oils
Since fat makes up the vast majority of your calories on keto, the oils and fats you cook with matter more than on any other diet. Olive oil and avocado oil are top choices because they’re rich in heart-healthy unsaturated fats and work well at medium to high cooking temperatures. Coconut oil is another popular option, especially for baking or sautéing at moderate heat.
Butter and ghee are common in keto cooking, though Harvard’s nutrition researchers recommend emphasizing unsaturated fats over saturated ones for long-term heart health. That means leaning more on nuts, seeds, avocados, and plant oils as your primary fat sources, and treating butter as a supporting player. Avoid anything containing trans fats, which are sometimes found in margarine and processed snack foods.
Meat, Poultry, and Seafood
Animal protein is a cornerstone of most keto meal plans. Beef, pork, lamb, chicken (especially thighs and legs with skin), and turkey all fit easily. Fattier cuts naturally align with keto’s high-fat requirements, but you don’t need to seek out the fattiest option every time. Pairing leaner cuts with a fat source like olive oil or cheese works just as well.
Fatty fish deserves special attention. Salmon, sardines, mackerel, and albacore tuna are rich in omega-3 fats, which help with blood sugar regulation and heart health. Aim for at least two 3-ounce servings of fatty fish per week. Shrimp, cod, and other shellfish are also carb-free and protein-rich.
Processed meats like bacon, sausage, and deli meat are technically allowed, but regular consumption is linked to higher cancer risk and poorer heart health. Use them as occasional additions rather than daily staples.
Low-Carb Vegetables
Non-starchy vegetables are your best friend on keto. A typical serving (half a cup cooked or one cup raw) contains about 5 to 6 grams of carbs and 3 grams of fiber, leaving you with only 2 to 3 grams of net carbs. That’s low enough to eat generously without jeopardizing ketosis.
Your go-to options include:
- Leafy greens: spinach, kale, arugula, romaine, Swiss chard, collard greens
- Cruciferous vegetables: broccoli, cauliflower, Brussels sprouts, cabbage
- Other low-carb picks: zucchini, asparagus, celery, mushrooms, cucumbers, green beans, bell peppers, eggplant, radishes
Onions and tomatoes are fine in moderate amounts, though they carry slightly more carbs than the options above. Starchy vegetables like potatoes, corn, and most winter squashes are too carb-dense and should be avoided or used very sparingly.
Fruits That Fit
Most fruit is too high in sugar for keto, but a few options work in small portions. Avocado is the standout: half an avocado contains less than 2 grams of net carbs thanks to its high fiber content, plus it delivers a generous dose of healthy fat. Technically a fruit, it’s one of the most useful foods on the entire diet.
Berries are the next best choice. One cup of halved strawberries has about 11.7 grams of total carbs, but after subtracting 3 grams of fiber, you’re looking at roughly 8.7 grams of net carbs. That’s manageable if you keep the rest of your day’s carbs low. Raspberries and blackberries have similar profiles. Watermelon is surprisingly moderate at 11.5 grams of carbs per cup, though it has less fiber than berries.
Peaches, grapes, bananas, mangoes, and pineapple are all too high in sugar to fit comfortably. A single medium peach contains 14.3 grams of carbs, and tropical fruits climb much higher.
Dairy Products
Full-fat dairy fits naturally into keto. Cheese is one of the easiest foods to incorporate because it’s high in fat, moderate in protein, and very low in carbs. Nearly all varieties work: cheddar, brie, mozzarella, goat cheese, cream cheese, Parmesan, feta, Swiss, gouda, and blue cheese are all solid choices.
Heavy cream and half-and-half are very low in carbs and useful in coffee, sauces, and soups. Plain Greek yogurt and cottage cheese contain some carbs but are acceptable in moderation. Choose full-fat versions and avoid anything flavored or sweetened, as those can contain 15 or more grams of sugar per serving.
For plant-based alternatives, unsweetened almond milk, coconut milk, and soy milk all work on keto. Skip oat milk, even unsweetened versions are too high in carbs.
Nuts, Seeds, and Eggs
Eggs are one of the most versatile keto foods. They’re virtually carb-free and provide both fat and protein. Eat them however you prefer, and don’t skip the yolk, that’s where most of the fat and nutrients are.
Nuts and seeds provide fat, fiber, and crunch, but carb counts vary significantly. Pecans, macadamia nuts, and walnuts are among the lowest in carbs. Almonds, pumpkin seeds, chia seeds, and flaxseeds are also good options. Cashews and pistachios are higher in carbs, so portion control matters more with those. Nut butters work too, as long as they don’t contain added sugar.
Keto-Friendly Sweeteners
If you need sweetness without the carbs, a few sugar substitutes are well-suited to keto. Stevia and monk fruit extract both contain zero calories and zero carbs, making them the cleanest options. Erythritol is a sugar alcohol that technically contains 4 grams of carbs per teaspoon, but research shows it doesn’t raise blood sugar the way regular carbs do, so most people don’t count it toward net carbs.
Xylitol is another sugar alcohol option with a similar profile to erythritol, though it’s toxic to dogs, so keep it out of reach if you have pets. Be cautious with sucralose (Splenda). The liquid form is carb-free, but the powdered packets contain small amounts of maltodextrin and dextrose, adding about 1 gram of carbs each. Avoid regular sugar, honey, maple syrup, and agave, all of which will kick you out of ketosis quickly.
Foods to Avoid
The biggest category to eliminate is grains and everything made from them: bread, pasta, rice, cereal, oats, tortillas, crackers, and baked goods. Even whole grains are too carb-heavy for keto. Beans and legumes (black beans, lentils, chickpeas) are also off the list despite being nutritious, because a single cup can contain 30 to 45 grams of net carbs.
Other foods to skip:
- Sugary drinks: soda, juice, sweetened tea, sports drinks
- Starchy vegetables: potatoes, sweet potatoes, corn
- Most fruit: bananas, grapes, mangoes, pineapple, dried fruit
- Sweetened dairy: flavored yogurt, sweetened condensed milk, ice cream
- Processed snacks: chips, pretzels, candy, most granola bars
Alcohol is a gray area. Dry wines and spirits have fewer carbs than beer or cocktails mixed with juice, but alcohol does pause fat burning temporarily while your body processes it.
Keeping Electrolytes in Balance
One thing that catches many new keto dieters off guard is electrolyte loss. When you cut carbs drastically, your kidneys excrete more sodium, and potassium and magnesium levels can drop along with it. This is the main cause of “keto flu,” the headaches, fatigue, and muscle cramps that sometimes hit during the first week or two.
The fix is straightforward. Aim for 3 to 5 grams of sodium and 3 to 4 grams of potassium per day. You can reach those targets by salting your food liberally, eating potassium-rich foods like avocados, spinach, and salmon, and using a lite salt (which is part potassium chloride) in cooking. Magnesium-rich foods like nuts and dark leafy greens help round things out. Getting electrolytes from whole foods rather than supplements is the most sustainable approach and keeps your meals naturally flavorful.