What to Eat on the Keto Diet

The keto diet eliminates all foods containing carbohydrates (except whole fruit) and requires you to choose nutrient dense whole foods that are rich in fat, protein and fiber. The diet also limits processed and prepackaged foods that contain sodium, saturated and trans fats. Ideally, the diet is made up of mostly animal products like grass-fed meats, dairy, whole eggs and fish but can be adapted for vegetarians with the addition of high-fat plant-based foods such as olive, avocado, canola, nut, and flax oils.

The diet allows small amounts of fruits and vegetables — particularly leafy greens, cruciferous vegetables (such as kale, Swiss chard, broccoli), and cauliflower, plus mushrooms, onions, peppers, and garlic. However, these foods are limiting because they provide very few calories and only modest amounts of fiber. A cup of chopped kale, for example, contains just six carbs.

When you follow the keto diet, your body will produce ketone bodies for energy. When the ketone levels get too low, your brain will alert you that you need more fuel. This is what causes the feelings of hunger and fatigue that often accompany the ketogenic diet.

The keto diet can be challenging for some people, especially if they have a medical condition that makes them sensitive to carbohydrates and/or fats. In these cases, making abrupt changes to a diet can cause uncomfortable side effects, such as brain fog, headache, nausea, tiredness and constipation.