Calories, BMR and TDEE: How Many Calories Do You Need?
Calories are simply units of energy. Your body uses them to breathe, think, digest food and move. Knowing roughly how many you burn each day makes it much easier to plan eating for weight loss, maintenance or muscle gain.
BMR: the energy of staying alive
Your basal metabolic rate is the energy you would burn lying still all day. It accounts for 60 to 70% of the calories most people use. A widely used estimate is the MifflinβSt Jeor equation: for men, BMR = 10 Γ weight (kg) + 6.25 Γ height (cm) β 5 Γ age + 5; for women, the same with β161 at the end.
TDEE: adding movement
Total daily energy expenditure is BMR multiplied by an activity factor: about 1.2 if you are mostly seated, 1.375 for light exercise, 1.55 for moderate exercise, 1.725 for hard exercise and 1.9 for very physical lifestyles. Try the calorie calculator to get your own numbers.
Setting a goal
- Maintain: eat close to your TDEE.
- Lose weight: a deficit of 250 to 500 calories a day typically leads to 0.25 to 0.5 kg (about half to one pound) per week.
- Gain muscle: a small surplus of 250 to 300 calories with strength training.
Avoid extreme deficits. Very low intakes can cause muscle loss, fatigue and nutrient gaps, and they are hard to maintain.
Why the number is only an estimate
Individual metabolism varies by several hundred calories. Muscle mass, genetics, hormones, sleep and medications all play a part. Use your estimate as a starting point, track your weight for two or three weeks and adjust by 100 to 200 calories if the trend is not what you expect.
Quality matters as well as quantity
Protein helps you feel full and protects muscle. Fibre-rich foods such as vegetables, beans and whole grains slow digestion. Liquid calories from sugary drinks add up quickly without keeping you satisfied.
Donβt forget hydration
Thirst is sometimes mistaken for hunger. Check the water intake calculator for a daily target based on your weight and activity.
If you have a medical condition, are pregnant, or are under 18, talk to a doctor or registered dietitian before changing your diet. This article is educational and not medical advice.