How Your Metabolism Changes in Your 20s, 30s, and 40s

When you’re a kid, you can wolf down candy bars, fast food, and frozen pizza bagels without a second thought—you know it

won't impact your weight. Now, you're a hardcore veggie eater and struggle to lose those extra few pounds. Why does this happen? As you likely know, your metabolism takes a nosedive over the years and ultimately impacts your waistline. Now that we've got that out of the way, here are all the ways your natural calorie-burning power transforms as you age—and what you can do to keep it in high gear.

In Your Twenties...