Researchers found that metabolism peaks around age 1, when babies burn calories 50 percent faster than adults, and then gradually declines roughly 3 percent a year until around age 20.

At what age does your metabolism slow down?

The data suggest that our metabolisms don't significantly decline again until after age 60. The slowdown is a little less than 1 percent a year, but once you reach your 90s, you'll need roughly 25 percent fewer calories every day than someone in midlife.

What age does your metabolism start to change?

For many people, the term metabolism really means metabolic rate — the speed at which your body burns calories to keep its basic functions running. Your metabolic rate does change during your early life, but it plateaus between the ages of 20 and 60, and only decreases by around 1% per year after that.