Your protein needs might not be a one-size-fits-all 0.8 grams per kilogram—research is all over the place.

The evidence on protein needs is mixed. Some studies show that after a certain amount, extra protein doesn't build more muscle—like one where 30 grams after a workout was as good as 45, and another where 20 grams was enough. But other research finds that 40 grams beats 20 grams. When it comes to the 0.8 guideline, part of the pushback is that it's based on studies of older, inactive men. Some research on older guys lifting weights suggests that doubling the recommended amount helps them gain more muscle and strength, which supports the idea that active people might need more. But other studies on active older women find no extra benefit from more protein. And while some reviews suggest protein needs could be as high as 2.2 grams per kilogram, other studies say around 1 gram is adequate. So the truth is, it likely depends on who you are and what you're doing.