If I were to ask you what your metabolism is, what would you say? I bet you would answer, "The way my body burns calories." If so, you would be wrong. That's one of the key things your metabolism does. But I'm asking whether you know what it is.
The answer is hormones! Your metabolism is your biochemistry. Some hormones tell you you're hungry; some tell you you're full. When you eat, hormones tell your body what to do with that food — whether to store it or burn it as fuel. And when you exercise, hormones tell your body how to move and consume energy stores, and how to boost or shut down different body parts. Hormones control almost every aspect of how we gain weight — and how we can lose it.
The endocrine system — the group of organs and glands responsible for releasing hormones that regulate key bodily functions — is sometimes compared to an orchestra. Each hormone is like an instrument. Playing together, in tune, they sound amazing. But what happens if, right in the middle of a concert, a violin suddenly goes wildly astray, twanging on its own? And then a clarinet starts shrieking? And then the pianist can't keep up? The music would sound like crap, right?
It's exactly the same with your metabolism. Your body can't work the way it's supposed to if any of your hormones is out of tune. Once one goes, they all follow. That's why you can't just focus on one hormone at a time when you're trying to balance your hormones — you have to work to get them all in tune and playing in the right key again.