Eating protein before bed won’t mess with your hunger or slow down your metabolism the next morning — so it’s safe to add to your daily routine if you're a healthy or overweight young guy.

Eating protein before bed doesn’t make you less hungry or slow down your metabolism the next morning — at least for healthy or overweight men.

If you're eating more protein overall, it might be that—not your bedtime snack—that's helping your muscles grow. So taking protein before bed might not be the real reason for better results.

For healthy older guys, working out in the evening and then having protein before bed helps their muscles use that protein better overnight than just having protein alone.

Eating 20 to 40 grams of protein before bed might help your muscles repair and grow overnight, especially if you also worked out in the evening.

If you're a young adult who's overweight or obese, having a casein protein shake before bed doesn't seem to change your metabolism or fat burning in any clear way — it doesn't help or hurt much, based on the studies so far.