Health Claims

If young guys who don't get enough vitamin D lift weights and take a daily combo of whey protein and a high dose of vitamin D, they'll gain more muscle — especially in their legs — than those who just lift weights without the supplements.

Causal

For young guys lifting weights, eating 1.8 grams of protein per kilo of body weight each day is enough to gain muscle and get stronger in 10 weeks — it doesn’t matter if they take a 35g casein protein shake during the day or before bed.

Causal

If young guys who lift weights drink a protein shake with 35 grams of casein every day — and keep training — they could gain about 2 to 2.8 kilos of muscle in 10 weeks.

Causal

If young guys lift weights in a structured way for 10 weeks, eat about 1.8 grams of protein per kilo of body weight every day, and have supervision, they can get way stronger—adding around 80–85 kg to their leg press and 11–12 kg to their bench press max lifts.

Quantitative

If young, active guys lift weights 4 days a week and eat the same total amount of protein, it doesn’t matter whether they have their casein protein late at night or earlier in the day — they’ll gain similar muscle and strength over 10 weeks.

Causal

If young, healthy guys lift weights for 12 weeks and drink protein before bed, their power-producing muscles might grow way more than if they don’t — like almost double the growth, according to this claim.

Causal

If young, healthy guys lift weights for 12 weeks and drink a protein shake before bed, they might gain more leg muscle than those who don’t — about the size of a small egg more.

Quantitative

If young, healthy guys lift weights for 12 weeks and drink a protein shake before bed, they gain more strength—about 34 kg more—compared to those who don’t, according to one study.

Quantitative

If you're already fit and eat a decent amount of protein, boosting your intake even higher with supplements won’t change your muscle, fat, or performance—as long as your workout routine stays the same.

Quantitative

If you're already working out, taking 54 grams of casein protein every day for 8 weeks—whether in the morning or at night—won’t noticeably change your strength or how long you can keep lifting weights, as long as your workouts stay the same.

Causal

If you're someone who works out regularly, adding 54 grams of casein protein to your daily diet—whether in the morning or at night—won’t make you gain fat over 8 weeks, even if you don’t change your exercise routine.

Causal

If fit people already eat a lot of protein, taking extra casein protein in the morning or before bed doesn’t change their body fat or muscle over 8 weeks—if their workouts stay the same.

Causal

If young, healthy guys eat 45 grams of protein before bed after a workout, their muscles build more energy-producing parts overnight compared to skipping the protein.

Mechanistic

Drinking 45g of either whey or casein protein before bed helps muscle recovery just as much after endurance exercise in young, healthy guys — neither one works better than the other.

Quantitative

If young, healthy guys eat 45 grams of protein before bed after a long run, their muscles repair and rebuild better overnight — whether they choose whey or casein protein doesn’t matter.

Causal

For female college athletes who lift weights, taking 24 grams of whey or casein protein before and after workouts for eight weeks leads to the same results in muscle, strength, and performance — so both types work just as well.

Causal

If female college athletes who lift weights drink a protein shake with 24 grams of protein before and after workouts for eight weeks, they’ll likely jump higher and farther.

Causal

If female college athletes who lift weights drink a protein shake with 24 grams of protein before and after workouts for eight weeks, they’ll get stronger in their upper body — especially if they use whey protein instead of casein.

Causal

If female college athletes who already lift weights add a specific workout plan and eat 24 grams of protein before and after each session, they’ll get way stronger in their legs—adding about 90 kg to their leg press max in just eight weeks.

Causal

If female college athletes who already lift weights drink a protein shake with 24 grams of protein right before and after their workouts for eight weeks — while following a specific 4-day workout plan — they’ll likely gain about 1.4 to 1.5 kg of muscle and lose 1 to 2% body fat.

Causal

If you're a healthy young adult, your muscles might use amino acids from supplements better than from real milk—scientists tracked this by seeing how much labeled phenylalanine ended up in muscle over 6 hours.

Quantitative

If you're a healthy young adult, drinking amino acids might help your body build more muscle in the hours after eating than drinking the same amount of protein from milk.

Quantitative

If you drink free amino acids, your insulin spikes more after the meal than if you drink the same amount of protein from milk — 35 vs 24 units on average.

Quantitative

If you're a healthy young adult, drinking a supplement with 30 grams of broken-down amino acids won't help your muscles grow more than drinking the same amount from real milk protein—even though your body absorbs the amino acids faster.

Mechanistic