How to use it
- Enter your daily calories, or switch to “My body data” to estimate them from sex, age, weight, height, activity and goal.
- Choose a split: balanced, low-carb or high-protein. Each fills in the three percentages, which you can then change.
- Read the grams of protein, fat and carbohydrate and how many calories each provides.
How it works
Grams = calories × percentage ÷ energy per gram, using the Atwater factors: 4 kcal/g for protein, 9 kcal/g for fat, 4 kcal/g for carbohydrate.
| Preset | Protein | Fat | Carbohydrate |
|---|---|---|---|
| Balanced | 20 % | 30 % | 50 % |
| Low-carb | 30 % | 45 % | 25 % |
| High-protein | 35 % | 25 % | 40 % |
The balanced preset is inside the Acceptable Macronutrient Distribution Ranges of the Institute of Medicine (2005); low-carb stays under the 26 % limit used to define low-carbohydrate diets (Feinman et al., 2015); high-protein sets protein at the top of its range.
From body data, calories = Mifflin–St Jeor BMR × activity factor, then −500 or +500 kcal for losing or gaining about 1 lb (0.5 kg) a week – the same method as the calorie calculator.
Worked example
2,000 kcal with the balanced split: protein 20 % = 400 kcal = 100 g; fat 30 % = 600 kcal = 67 g; carbohydrate 50 % = 1,000 kcal = 250 g.
Tips
- Protein needs are often also expressed per kilogram of body weight; check your grams against that if you train hard.
- The numbers are targets for a typical day, not rules to hit exactly. Food labels and apps round values.
- With diabetes, kidney disease or other conditions, agree changes in diet with a doctor or registered dietitian.