Browse evidence-based analysis of health-related claims and assertions
Protein shakes make your body burn a little more calories at rest and after eating, but this doesn’t help you keep the weight off.
Mechanistic
Taking extra protein shakes after losing weight doesn’t help you keep the weight off any better than eating the normal amount of protein in your daily diet.
Causal
When people eat more protein, their blood shows higher levels of a waste product called urea, which means their body is breaking down more protein than usual.
Instead of eating lots of white bread or sugary snacks, swapping them for lean protein like chicken or beans might help you manage your weight and stay healthier.
Descriptive
Some studies show that eating more protein helps people lose more weight and body fat, but not all studies agree on this.
Meals with more protein tend to make people eat less at their next meal.
Eating more protein makes you feel fuller for longer, so you’re less likely to snack or eat too much later.
Eating more protein makes your body burn a bit more calories just to digest it, compared to eating less protein.
When you eat more protein after losing weight, your body holds onto more muscle instead of breaking it down.
After losing weight, your body tries to burn fewer calories than it should — but eating more protein helps your body return to its normal calorie-burning rate.
When your muscles get really tired during a workout, your body has to turn on more muscle fibers to keep going — and that might help them grow bigger.
When your muscles swell up from fluid buildup during a tough workout, that pressure might send signals to your cells to grow bigger — even if you’re not lifting heavy weights.
Working out until you're exhausted might make your body release more growth hormone and testosterone, which could help your muscles grow — but we’re not sure if these hormones actually cause the growth.
You can make your muscles grow bigger by lifting very light weights if you restrict blood flow to your arm or leg — it tricks your body into thinking you’re lifting heavy.
When you lift weights until your muscles burn and feel fatigued, the buildup of waste products might help your muscles grow bigger, but the main reason they grow is still from the physical force you're using.
Starting your workout with big lifts like squats and bench presses doesn’t make you stronger or change your body differently than starting with small lifts like leg extensions — as long as you train hard for 12 weeks.
No matter the order of exercises, people who were already trained got much stronger after 12 weeks of lifting — all groups improved a lot.
Doing isolation exercises before compound lifts (like leg extensions before squats) doesn’t make you stronger or change your body more than doing the lifts in a different order, as long as you’re already trained.
When athletes are trying to lose weight by eating fewer calories, eating more protein (about 2.3 grams per kilogram of body weight) helps them keep more of their muscle compared to eating less protein (about 1 gram per kilogram).
People with more active brown fat burn over twice as many extra calories after eating carbs as people with less active brown fat — this could explain why some people stay leaner even when eating the same food.
Quantitative
People with more active brown fat burn more calories after eating carbs — the more active their brown fat, the more energy they burn.
Correlational
Eating fatty foods doesn’t make your body burn many extra calories — and your brown fat doesn’t seem to help with it.
Eating a high-protein meal makes your body burn more calories afterward than eating carbs or fat — but this doesn’t depend on how active your brown fat is.
After eating carbs, people with more active brown fat keep burning extra calories for the full two hours afterward, not just right after the meal.