If middle-aged Japanese women eat more protein at breakfast over time while strength training, they may gain more muscle — but if they already eat a lot of protein at breakfast to start with, they might not gain as much.

If middle-aged Japanese women who are doing strength training start eating more protein at breakfast—especially if they weren’t eating much before—they’re likely to gain more muscle.

For older guys in their 60s and 70s who already eat enough protein, taking 40 grams of protein right after working out or just before bed doesn’t help build bigger leg muscles any more than just working out — the muscle gains are about the same no matter when they take it.

If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of body weight every day is the biggest factor that helps — more protein means better results, and when you eat it doesn't matter as much.

When young women who are new to weight training do more sets and lifts, and eat at least 1.5 grams of protein per kilogram of body weight, they tend to gain more muscle than those who don’t get enough protein.

If you're lifting weights and want to build muscle, eating at least 1.6 grams of protein per kilogram of your body weight every day is the most important thing — and eating even more protein (like 0.5 extra grams per kg) helps you gain a little more muscle on top of that.