Browse evidence-based analysis of health-related claims and assertions
People with metabolic syndrome who follow intermittent fasting see their body mass index drop by a small but measurable amount, meaning they’re losing fat relative to their height.
Causal
People with metabolic syndrome who try intermittent fasting lose about 4 pounds on average after a few months, even without counting calories.
After a few months of intermittent fasting, the body’s resistance to insulin drops by a measurable amount, making it easier for cells to absorb sugar from the blood.
People with metabolic syndrome who follow intermittent fasting see their body’s insulin levels drop, meaning their body is better at using insulin to manage blood sugar.
After a few months of eating only during certain hours, people with metabolic syndrome see a tiny but real drop in their average blood sugar levels over time.
Skipping meals at certain times of the day for a few months can slightly lower blood sugar levels in people with metabolic syndrome.
A protein in the brain called BDNF plays a big role in how well we think, learn, and remember things.
Descriptive
Sometimes skipping meals might help animals live longer and stay healthier by triggering a mild stress response in their cells.
We don’t know yet if skipping meals sometimes helps human brains work better — we need more studies to find out.
In mice and rats, eating only at certain times of day (like skipping meals sometimes) seems to boost a brain protein that helps with memory and thinking.
As people get older, their brain makes less of a helpful protein called BDNF, which can make it harder to remember things and learn new stuff, and may raise the chance of dementia.
People who eat more often during the day tend to drink less alcohol relative to their total food intake.
Correlational
Even when men ate the same number of total calories, those who ate fewer meals were still more likely to be obese, meaning it’s not just about how much they eat, but when and how often.
People who eat fewer meals are more likely to under-report how much they eat, which could make it harder to study their true eating habits accurately.
Even when researchers accounted for people eating lots of sweets and junk food, those who ate fewer meals still had higher obesity rates, meaning the problem isn’t just about what they snack on.
People who snack and eat more often tend to eat more fruits, veggies, and whole grains, which are rich in fiber and vitamins.
Men who eat fewer meals are more than twice as likely to have a very large waistline, even if they eat the same number of calories as men who eat more often.
People who eat more often during the day tend to get more of their calories from carbs and less from alcohol, which is generally considered healthier.
For women in this study, how often they ate didn’t seem to affect whether they were obese or had a large waist, unlike in men.
Men who eat fewer meals per day are more likely to smoke, drink more alcohol, and be less physically active than men who eat more often.
Men who eat more often during the day tend to consume more fiber and less fat in their diet, which are signs of healthier eating habits.
Men who eat only three meals or fewer a day are more than twice as likely to be obese compared to men who snack and eat more often, even when they eat the same total amount of food.
After four days of eating only until 2 p.m., people lost a tiny bit of weight—about half a pound—mostly from water and stored carbs, not fat.
Even though people might not remember exactly when they ate, the general patterns of when and how often they eat still line up with whether they gain or lose weight over time.