Measurement study — 1990 — Energy balance
A new predictive equation for resting energy expenditure in healthy individuals
What did the researchers investigate?
An equation for resting energy expenditure, derived from 498 healthy men and women aged 19-78, normal-weight and obese, measured by indirect calorimetry.
What did they find?
Resting energy expenditure was predicted from weight, height and age for each sex (10 × weight in kg + 6.25 × height in cm − 5 × age, + 5 for men or − 161 for women). The older Harris-Benedict equations overestimated measured values by 5%.
What does this mean for training?
Resting energy needs can be estimated from basic body measurements, without a lab.
How does FitX AI use this evidence?
FitX AI uses this exact equation for your BMR, the starting point of your daily calorie target.
Where FitX AI's own choices go beyond this paper
Calorie target. Activity multipliers and training energy are approximations. The target is an estimate and your real progress is the check. A typed target is the user's own number: FitX AI makes no claim for it, and its 1,200-6,000 kcal range and BMR warning are product choices.
Limitations
An estimate for groups: individuals can differ. It does not use body composition, which predicted resting needs best in the same study.