Browse evidence-based analysis of health-related claims and assertions
The combined effect of consuming whole foods and hydrating in a fasted state increases daily energy expenditure by 100–150 kcal compared to consuming ultraprocessed foods and not hydrating in a fasted state.
Quantitative
A daily caloric surplus of 64 kcal from reduced postprandial energy expenditure due to ultraprocessed food consumption results in approximately 1 pound of fat gain per month.
Water-induced thermogenesis is significantly greater in metabolically inflexible, overweight individuals compared to metabolically healthy individuals.
Comparison
Elevated insulin levels suppress fat oxidation, thereby inhibiting the fat-burning effects of hydration.
Assertion
Hydration in a fasted, low-insulin state significantly enhances fat oxidation compared to hydrated states following carbohydrate intake.
Food processing reduces the metabolic cost of digestion by pre-masticating and simplifying nutrient structures, thereby increasing net energy absorption.
Consuming whole foods increases postprandial energy expenditure compared to isoenergetic ultraprocessed foods due to higher digestive effort and reduced thermodynamic efficiency.
Processed foods are easier for your body to break down because they’re stripped of fiber and nutrients — so your body doesn’t have to work as hard, which means fewer calories burned.
Mechanistic
The sandwich made with real bread and cheese has about three times more fiber than the one made with white bread and processed cheese — and that extra fiber might make your body work harder to digest it.
Descriptive
Even though one sandwich is made with real ingredients and the other with processed stuff, people feel just as full after eating both — the body doesn’t tell the difference in fullness.
Your body keeps burning calories longer after eating a sandwich made with real ingredients than after eating one made with processed stuff — about an extra hour.
Eating a sandwich made with real bread and real cheese burns almost twice as many calories during digestion as one made with white bread and processed cheese, even if both have the same number of calories.
If overweight people swap soda for water, they gain less weight—but if they swap water for milk or juice, they gain more weight, showing what you drink matters more than just how much you drink.
Correlational
Giving kids or adults water instead of soda doesn’t usually make them lose weight if they just eat more food to make up for the missing calories.
When overweight people on a diet drink more than a liter of water a day, they tend to lose more weight—even if they don’t eat less—possibly because water helps their body use insulin better and reduces cellular stress.
When you drink water instead of sugary drinks while resting or walking, your body burns more fat because sugar in drinks tells your body to stop burning fat and start storing it.
When overweight or obese people drink a glass of water on an empty stomach while sitting still, their body burns a few extra calories, possibly because the water makes their cells swell and wake up their metabolism.
When people drink water instead of soda, juice, or milk with their meals, they tend to eat less food overall, so they take in fewer calories.
The combo of L-arginine and sodium butyrate raised the appetite hormone more than L-arginine alone — but we don’t know if that difference was real or just luck.
Even though the supplements raised a hormone linked to fullness, people didn’t feel any less hungry or more full after eating.
Taking L-arginine or L-arginine plus sodium butyrate didn’t change blood sugar levels after eating in obese people — even though it raised one appetite hormone.
Taking just L-arginine before a meal might slightly raise the appetite-regulating hormone GLP-1 in obese people, but the result was too weak to be sure it wasn’t just random chance.
Giving obese people a one-time mix of L-arginine and sodium butyrate before eating made their body release more of a hormone (GLP-1) that helps control blood sugar and appetite — but only for that one meal.
Even though hunger and fullness hormones are different in older women, those differences don’t match up with who eats less—so the problem probably isn’t the hormones themselves.