How many calories do you need?
Short answer
Estimate your resting energy expenditure with the Mifflin-St Jeor equation and multiply it by an activity factor. To lose fat, eat about 300–500 kcal below that; to build muscle, about 200–300 kcal above. These ranges are common practical values; your weight trend shows whether they fit.
Figures
- 0.5–1% · weight loss per week when dieting
- −300 to −500 · kcal per day to lose fat (practical value)
- +200 to +300 · kcal per day to gain (practical value)
- 1,780 kcal per day: Resting
- 2,260 kcal per day: Fat loss (−500)
- 2,760 kcal per day: Maintenance (× 1.55)
- 3,010 kcal per day: Gain (+250)
The equation
Men: 10 × kg + 6.25 × cm − 5 × age + 5. Women: the same, but −161 instead of +5. Multiply the result by 1.2 for little activity up to about 1.7 for a lot. The factors are a convention and rough.
The scale corrects the equation
Weigh yourself in the morning and compare weekly averages. If your weight stays flat for 2–3 weeks, you have found maintenance. Then adjust in steps of 100–200 kcal.
Rate of fat loss
For lifters, Helms and colleagues recommend 0.5–1% of body weight per week. Slower protects muscle better. Keep training heavy in a deficit and keep protein high.
Rate of gain
A large surplus mostly adds fat. Trained lifters gain muscle slowly; a small surplus is enough.
Sources
- Mifflin et al. · 1990 · Am J Clin Nutr DOI
Origin of the resting energy equation.
- Helms, Aragon, Fitschen · 2014 · J Int Soc Sports Nutr DOI
0.5–1% weight loss per week in contest preparation.
- Resistance training volume does not influence lean mass preservation during energy restriction in trained males · Roth C; Schwiete C; Happ K; Rettenmaier L; Schoenfeld BJ; Behringer M · 2022 · Scand J Med Sci Sports PubMed DOI
- Thomas, Erdman, Burke · 2016 · Med Sci Sports Exerc DOI
Energy availability and body composition in athletes.
Summaries by SetCtl, not medical advice.