For Strong Muscles, Eat Spinach: It's Full of Iron
How true is the claim? Only partly. Muscles need some iron to produce energy, but protein is more important for muscle building.
Why it gets repeated: Hey, it worked for Popeye. But the sailor should have traded his can of spinach for one of Wimpy's protein-packed hamburgers. Not only does protein help repair and rebuild muscle but meat is also a better source of iron than spinach. Only 2 to 20 percent of nonheme iron (the kind found in plants) is absorbed by the body, compared with 15 to 35 percent of the heme iron found in animal products, such as beef, chicken, and turkey.
Bottom line: You need both protein and iron to build strong muscles. There are lots of other compelling reasons to eat spinach; it's a great source of antioxidants, including vitamin C.