The keto diet is a high-fat, moderate-protein, super-low-carb diet. When your body is running on so few carbs, it enters a state of ketosis, during which it starts burning fat for fuel instead of glucose (your body processes glucose from carbs).
On the keto diet, the macronutrient profile should be close to 70 to 80 percent fat, 15 to 20 percent protein, and five to 10 percent carbs, according to Catherine Metzgar, PhD, RD, a clinical team member at Virta Health. You should aim to keep your carbs at 50 grams a day or fewer, although every person is different and may have varying thresholds of ketosis.
If you aren't sure if your body is in ketosis, you can test it with urine strips, which let you know how many ketones your body is producing.