Imagine trying to finish a puzzle — only you’re missing nine key pieces. Your dazzling 1,000-piece remake of that Grand Canyon sunset is almost complete, but it’s missing the sun. Frustrating, right?

That’s how your muscles feel without complete proteins.

Protein is made up of tiny bits called amino acids. Your body can make most of these on its own, but there are nine essential amino acids that you need to supply via your diet.

Beans are a rich source of eight of those essential amino acids. But most fall short of that key ninth protein ingredient — it’s an amino acid called “methionine.”

The good news? Beans + other delicious foods will get you on the fast track to getting the complete proteins your muscles crave. This guide will show you three powerful combos to get the protein you need.