Browse evidence-based analysis of health-related claims and assertions
What you eat in one meal matters more for how many calories you eat that day than how hungry or full you feel.
Correlational
When people on a high-protein diet eat a meal they choose themselves, their total calories go up — but they don’t feel any different in hunger or fullness.
Descriptive
Eating less protein makes people eat more calories — but not because they feel hungrier. Something else is going on.
How full or hungry people feel doesn’t explain why they eat more or less after choosing their own meal.
People on a high-protein diet usually pick one meal a week to eat whatever they want — and when they do, they eat more that day but don’t feel any hungrier or fuller than usual.
People can eat a lot more without feeling hungrier — meaning something other than hunger might be making them eat more.
Even when people eat more or less than usual because they chose a different meal, they don’t feel hungrier or fuller than normal.
When people eat a meal with less protein than usual, they tend to eat more total calories that day — and this pattern holds up even when accounting for other factors.
The day after eating a meal with less protein than usual, people tend to eat about 60 fewer calories than normal.
When people eating a high-protein diet skip their planned meal and choose something with less protein, they tend to eat about 260 more calories that day.
The daily changes in body temperature and hormones in pregnant cows aren’t controlled by just one clock — they’re shaped by at least two different timing systems working together.
As cows get closer to giving birth, their bodies start showing stronger daily patterns in stress hormones, pregnancy hormones, and mood-related chemicals — but only if they’re on a steady light schedule.
When cows are exposed to shifting light schedules before birth, their daily body temperature and hormone patterns change — and those changes are connected to them carrying their calves longer than usual.
Before giving birth, cows have daily rhythms in body temperature and key hormones, but after birth, these daily patterns disappear, no matter if their light schedule was changed or not.
When cows are kept on a changing schedule of light and dark before giving birth, their bodies produce less serotonin and more melatonin, which might affect how their internal clocks work.
These results only apply to healthy, young, professional adults — we don’t know if they’d work for older people, shift workers, or those with health problems.
Eating a high-protein breakfast made people sleep less, but they felt like they slept better and fell asleep faster — even though their actual sleep quality didn’t change.
Causal
Even though people slept less after eating a high-protein breakfast, their sleep was just as deep and uninterrupted — they just went to bed and woke up earlier.
The benefits of a high-protein breakfast on hunger and eating habits only showed up after eating it every day for a week — one meal wasn’t enough.
After eating a high-protein breakfast, people didn’t eat more protein later — they just ate less carbs and fat.
Even though people slept less after eating a high-protein breakfast, they didn't wake up more often or have worse sleep quality — their sleep was just shorter.
People who eat a high-protein breakfast might feel like they fell asleep faster and slept better, but the numbers aren't strong enough to say for sure.
People who eat a high-protein breakfast sleep about 36 minutes less per night than when they skip breakfast, but the quality of their sleep doesn't change.
People who eat a high-protein breakfast may eat about 420 fewer calories later in the day than those who skip breakfast, mostly because they eat less carbs and fat.