Ketogenic foods

A practical companion to the overview: the foods that fit a ketogenic plate, the ones that need portion control, and the ones that break ketosis, with the carb numbers behind each verdict. The list is organized by verdict.The list is organized by verdict rather than by store aisle, because the question is always the same — how much digestible carbohydrate reaches the blood, counted as net carbsnet carbs: total carbohydrate minus fiber and sugar alcohols, which pass through largely undigested; the 20-to-50-gram daily budget is counted this way — while the store aisle tells you nothing. Numbers are approximate, drawn from USDA data; brands vary, so the label outranks the list.

Friendly: the core of the plate

• Fats and oils carry the plate.Fats and oils carry the plate: olive oil, butter, ghee, heavy cream, coconut oil, avocado oil, and the traditional animal fats — lard, tallow, bacon drippings — with essentially zero digestible carbohydrate.
• Meat, fish and eggs are the protein.Meat, fish and eggs are the protein: beef, pork, lamb, poultry with the skin, and fatty fish — salmon, sardines, mackerel — plus eggs, all essentially carbohydrate-free; the exceptions are prepared versions — honey-glazed hams, breaded cutlets, sugar-cured bacon — where the sugar comes from the processing, not the food.
• Above-ground vegetables are the carbohydrate budget.Above-ground vegetables are the carbohydrate budget: leafy greens — spinach, kale, lettuce, arugula — plus broccoli, cauliflower, zucchini, asparagus, mushrooms, peppers and cabbage, typically one to four net grams per serving; the rule of thumb is that what grows above ground is generally fine and what grows below ground usually is not, which is why green beans fit even though their cousins the beans do not.
• Full-fat cheese and cream fit.Full-fat cheese and cream fit: cheddar, mozzarella, brie, cream cheese, sour cream and heavy cream carry only trace carbohydrates, and plain full-fat yogurt works in small servings; the dairy exceptions are milk and anything flavored or labeled low fat.
• Avocados and olives are staple produce.Avocados and olives are staple produce — high in fat, low in net carbs, the fruits keto agrees with.
• Nuts and seeds fit in measured handfuls.Nuts and seeds fit in measured handfuls: macadamias, pecans, walnuts, Brazil nuts, almonds, chia and flax run from about one to four net grams per ounce, though cashewscashews, the high-carb outlier at roughly nine net grams per ounce — more than half a cup of raspberries climb much higher and are counted with the borderline foods.
• Berries are the allowed fruit, in portions.Berries are the allowed fruit, in portions: half a cup of raspberries or blackberries runs about three to four net grams, and a few strawberries about the same, which fits the daily budget where larger fruits do not.
• Drinks are water, coffee and tea.Drinks are water, black coffee and unsweetened tea, plus bone broth; everything sweetened is covered below.

Borderline: fits in counted portions

These foods fit only in counted portions.These foods fit only in counted portions — too much carbohydrate for an unrestricted plate, too little to ban entirely.

• Everyday vegetables like carrots, onions and tomatoes are borderline.Everyday vegetables like carrots, onions and tomatoes are borderline: a medium carrot is about five net grams, half an onion four or five, and a tomato similar, so they season a dish freely but are no longer free themselves.
• Milk and fruit yogurt are borderline too.Milk and fruit yogurt are borderline too: a cup of milk carries about twelve grams of lactoselactose, the sugar of milk — glucose and galactose joined together, which digests into glucose as surely as table sugar, and flavored yogurts can double that, so they are occasional cups rather than daily glasses.
• Very dark chocolate is borderline.Very dark chocolate is borderline: a bar at 85 percent cacao runs around ten net grams per hundred grams, so a few squares fit, while milk chocolate is confectionery.
• Peanuts are the borderline legume.Peanuts are the borderline legume: botanically a legume but metabolically closer to a nut, at roughly two and a half net grams per ounce they are widely eaten on keto — plain and roasted, never honey-coated.
• Whole fruit beyond berries is portion-controlled.Whole fruit beyond berries is portion-controlled: a few slices of apple or melon fit a budget, but a medium banana carries about twenty-seven grams of carbohydrate and a medium apple about twenty-five, so one piece of most fruit is the whole day's allowance.

Not friendly: out

These foods end ketosis at ordinary portions.These foods end ketosis at ordinary portions — the sugars, the starches, and the drinks and products that carry them.

• Sugar in every form is out.Sugar in every form is out: table sugar, honey, maple syrup, agave and coconut sugar are all glucose or fructose wearing different clothes — honey is no better than sugar, and agave is mostly fructose — plus candy, cake, ice cream, jam and everything baked with them.
• Grains and flour products are out.Grains and flour products are out: bread, pasta, rice, oats, cereal, crackers, tortillas and anything made from wheat flour — a slice of bread is about fifteen grams of carbohydrate and a cup of cooked rice about forty-five, so neither survives a fifty-gram day.
• Root vegetables and starches are out.Root vegetables and starches are out: potatoes and sweet potatoes, beets, parsnips, corn and peas — a medium potato is about thirty-seven grams of carbohydrate, and the body treats it as bread.
• Legumes are out.Legumes are out: beans, lentils, chickpeas and split peas run twenty-five to thirty-five net grams per cooked cup; the pod vegetables — green beans, snow peas — are the exception and count with the friendly vegetables above.
• Fruit beyond berries is effectively out.Fruit beyond berries is effectively out at ordinary portions — bananas, apples, grapes, mangoes, oranges and pineapples — and fruit juice is out outright, being the fruit's sugar with none of its structure.
• Sugared drinks are the fastest way out of ketosis.Sugared drinks are the fastest way out of ketosis: juice and regular soda run twenty-five to forty grams a glass, a beer about thirteen, and sports drinks, sweetened coffee drinks and sweet cocktails land in the same range — liquid carbohydrate with no food to slow it.
• Low-fat products are usually sugar in disguise.Low-fat products are usually sugar in disguise: when fat is removed from yogurt, salad dressing, peanut butter or baked goods, starch or sugar replaces it, so anything labeled low fat, light or fat-free deserves a label check.
• Products labeled "keto" are not automatically friendly.Products labeled keto are not automatically friendly: keto-branded bars, cookies and breads often lean on sugar alcohols and added fibers of varying digestibility, and some raise blood glucose anyway, so the carbohydrate line on the nutrition label matters more than the word on the front.
• Hidden sugars hide in savory packages.Hidden sugars hide in savory packages: ketchup, barbecue sauce, teriyaki, honey mustard, marinara, salad dressings and glazed or honey-cured meats all add sugar, and spice mixes and "sugar-free" products can carry dextrose or maltodextrindextrose or maltodextrin, corn-derived sugars that raise blood glucose as fast as table sugar — dextrose scores near the top of the glycemic indexglycemic index, a scale of how quickly a food raises blood glucose; dextrose scores about as high as pure glucose, so the ingredient list is worth reading even where you expect none.

Sources

• USDA FoodData Central — the carbohydrate numbers behind the approximations above; the overview lists the study literature.
• Diet Doctor — visual low-carb guides — per-food net-carb guides, cross-checked against the USDA data.
• Harvard T.H. Chan — Ketogenic Diet review — the "what to limit" framing.