How much energy do I need?

How the app calculates

First the app estimates your resting energy expenditure, the energy your body uses at rest. It uses the Mifflin-St Jeor formula.^[1]

• Male: 10 × weight in kg + 6.25 × height in cm − 5 × age + 5^[1]
• Female: 10 × weight in kg + 6.25 × height in cm − 5 × age − 161^[1]
• Not stated: the same calculation with −78 at the end. This is the mean of the two constants and our own choice, not part of the study.^[1]

The app then multiplies this value by a factor for your everyday life.

Everyday life and exercise

If you are active for 30 to 60 minutes on four to five days a week, the German consumer advice centre adds 0.3.^[3]

EFSA uses the same factors, but with other formulas for resting expenditure.^[2] Combining them with Mifflin-St Jeor is our decision.

An example

Example: female, 40 years, 170 cm, 70 kg, partly sitting. Resting expenditure is 1,401.5 kcal. Times 1.6 gives about 2,240 kcal. The app shows this as 2,000 to 2,450 kcal.^[1][3]

What the formula does not know

The formula comes from measurements of 498 healthy people aged 19 to 78.^[1] In a systematic review it fell within 10% of the measured value more often than other common formulas. The authors still warn of notable errors for individuals. Older adults and ethnic minorities in the US were underrepresented in the studies.^[4]

The estimate is a guide. If you know your needs better, enter them yourself. The app sets no weight-loss goal and no calorie deficit. See also Why the app shows ranges.