Keto

Out of bounds are sugar, honey, bread, pasta, rice, oats, corn, potatoes, beans and lentils, and most fruit apart from small portions of berries. Sweetened yogurts, milk, beer, sweet wines, and anything breaded or battered also push you over the carb limit. Even seemingly savory items like ketchup, barbecue sauce, and many salad dressings contain hidden sugars worth checking on the label.

Most people aim for 20 to 50 grams of net carbs per day, where net carbs equal total carbohydrates minus fiber. A stricter version, sometimes called strict keto, keeps carbs under 20 grams to maintain consistent ketosis. The exact ceiling depends on body size, activity level, and how quickly an individual produces ketones.

Most fruit is too high in sugar, but berries fit in small portions: about half a cup of raspberries has roughly 3 grams of net carbs, and strawberries and blackberries are similar. Avocado and olives are technically fruits and are keto staples thanks to their fat content and very low net carbs. Bananas, grapes, mangoes, and apples are typically avoided because a single serving can use up the day's carb budget.

In the first one to two weeks, many people experience the so-called keto flu: fatigue, headache, irritability, and muscle cramps, mostly linked to sodium, potassium, and magnesium loss as insulin levels drop and the kidneys excrete more water. Constipation can occur if fiber intake is low, so non-starchy vegetables, chia, and flaxseed help. LDL cholesterol can rise in some individuals, which is worth monitoring with a clinician if you stay on the diet long term.