What does it actually mean to “listen to your body”? And why is it such a big deal?

What does it actually mean to “listen to your body”? And why is it such a big deal?

You know what it’s like. Having that friend who can eat taco bell, drink vanilla bean frappuccunios and snack on gummy worms all day but STILL has washboard abs year-round. Meanwhile you work hard to stay in shape, eat right, not too much and make an effort to workout (sometimes) but for some reason, you never look like her. I used to do the EXACT same thing for years - until I learned the holy grail of what it actually means to listen to MY body.