Does your metabolism slow down with age?

Reviewed 2 November 2026 · How these numbers are calculated

Less than most people think. A large study of over 6,000 people (Pontzer and colleagues, 2021) found that, once body size and muscle are accounted for, energy expenditure stays fairly stable from about 20 to 60, then falls by roughly 0.7% a year. Middle-age weight gain is mostly about moving less, losing muscle and changing habits. The everyday formula takes off about 5 calories a day per year: for a woman of 70 kg (154 lb) at 6,000 steps, about 120 calories a day less at 50 than at 30.

Resting burn and TDEE by age

Same body size at every age, 6,000 steps a day
Age	Woman BMR70 kg	Woman TDEE	Man BMR85 kg	Man TDEE
20	1,470	1,960	1,870	2,490
30	1,420	1,890	1,820	2,430
40	1,370	1,830	1,770	2,370
50	1,320	1,770	1,720	2,310
60	1,270	1,710	1,670	2,250
70	1,220	1,650	1,620	2,190
80	1,170	1,590	1,570	2,130

Mifflin-St Jeor and the Deficitly engine; woman 165 cm, man 178 cm. In real life, body composition and activity change with age too.

What the 2021 study found

The researchers measured total daily energy expenditure with doubly labelled water, the gold-standard method, in people from 8 days to 95 years old. Adjusted for body size, expenditure peaked in infancy, declined slowly through childhood and the teens, held roughly steady through adulthood from about 20 to 60, and declined gradually after 60. They found no sharp drop at menopause or in midlife.

So why do people gain weight with age?

Less movement: fewer steps, more sitting, less sport. This is the biggest change for most people; see NEAT.
Muscle loss: without strength training, muscle slowly declines, and with it resting burn.
Habits: bigger portions, more eating out, more alcohol, worse sleep.

What helps

Strength training two or three times a week keeps muscle: see lifting weights.
Enough protein, especially when eating less: how much protein you need.
Daily steps: the easiest lever for calories burned at any age.
Recalculate your maintenance every few years, or after changes in weight or activity.

Menopause

Many women notice weight gain around menopause. The 2021 study found no sudden metabolic drop at that age, but the hormonal changes often bring muscle loss, more fat around the middle, poorer sleep and lower activity. Strength training, protein and steps help most; see menopause weight gain and how many calories a woman should eat.

Sources

Pontzer H, Yamada Y, Sagayama H, et al. Daily energy expenditure through the human life course. Science 2021;373(6556):808–812.
Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr 1990;51(2):241–247.