生酮饮食宏量素计算器

The 70/25/5 ketogenic macronutrient split

The classical ketogenic ratio popularized by researchers Jeff Volek and Stephen Phinney allocates roughly 70 to 75 percent of calories to fat, 20 to 25 percent to protein and 5 to 10 percent to carbohydrate. On a 2000 kilocalorie diet this translates to about 156 grams of fat, 100 grams of protein and 25 grams of net carbohydrate per day. The goal is to deplete liver glycogen and shift hepatic metabolism toward producing ketone bodies such as beta-hydroxybutyrate, which most tissues can use as an alternative fuel. Nutritional ketosis is typically defined as blood beta-hydroxybutyrate between 0.5 and 3.0 millimoles per liter. This calculator sets fat as the balancing macro after fixing protein at a floor of roughly 1.4 to 1.8 grams per kilogram of lean body mass to protect muscle during carbohydrate restriction, and carbohydrate at 20 to 50 grams net per day depending on individual tolerance.

Net carbs, protein targets and adaptation timeline

Net carbs equal total carbohydrate minus fiber and sugar alcohols such as erythritol. Most keto protocols cap net carbs at 20 to 30 grams per day for the induction phase, which reliably produces ketosis within three to seven days. Protein often gets underdosed on keto because of outdated fears that excess protein breaks ketosis through gluconeogenesis. Evidence shows gluconeogenesis is demand-driven, not supply-driven, so eating 1.6 grams of protein per kilogram of body weight is safe and helps preserve muscle. The first two weeks of keto commonly produce transient symptoms known as keto flu: fatigue, headache, dizziness and irritability driven by electrolyte shifts and glycogen depletion. Supplementing sodium at 3 to 5 grams, potassium at 3 to 4 grams and magnesium at 300 to 400 milligrams daily during adaptation largely prevents these symptoms. Full metabolic adaptation takes three to six weeks.

常见问题