If you want to maximize your potential with nutrition, you need to know a lot more than a few key ratios and when to eat what. Breaking down the science of nutrition is confusing and wisdom about what’s good for you and what’s bad for you is constantly evolving—remember when we were supposed to avoid fat like the plague? But there’s some science around nutrition that has become cannon, and we’re here to help you sort through all the information (and misinformation) that’s out there.

You’ve got your training dialed in, but does what you put on your plate still have you scratching you head? Get to know each of these four major macronutrients as if they were your four favorite workouts: what they do in your body, how they work best, and if they serve you any deeper purpose beyond just making you look like a boss.