For a standard keto diet, you should be looking at somewhere between 5-10% of your calorie allowance provided by carbohydrates. If your daily calorie count is 2000, then 5-10% is calories. Nutrition packed vegetables like kale, cauliflower, and broccoli contain carbohydrates but they are allowed on a keto diet because the carbohydrates exist as fiber and can be subtracted. On the other hand, potatoes and corn are a no-no because they contain huge amounts of starchy carbs and less fiber. There is almost always a reduction in performance levels when you adjust to a keto diet.