Health Claims

Taking a specific green tea extract pill every day for a month helped young guys who exercise casually lose a little body fat—without losing any overall weight—while those taking a fake pill didn’t.

Causal

Taking a specific green tea extract every day for four weeks helps your body burn more fat while you exercise—without making you burn more total calories—so your body uses fat as fuel more efficiently.

Causal

Fat cells before they fully form have special receptors that can detect stress hormones like cortisol, and these receptors work about the same way as they do in other parts of your body — meaning they’re ready to respond when needed.

Descriptive

Women’s belly fat cells have fewer receptors for stress hormones than men’s, which might mean their fat tissue responds differently to stress.

Descriptive

In women, the fat cells around the belly have fewer receptors for stress hormones than the fat cells under the skin, which might explain why belly fat builds up differently than other kinds of fat.

Descriptive

A chemical called Atglistatin works really well to block a fat-burning enzyme in mice—by 95%—but it barely does anything to the same enzyme in humans, so it probably won’t work as a weight-loss drug for people.

Mechanistic

When scientists block a fat-burning enzyme called ATGL with a drug in mice, their hearts don’t get fatty or stop working—unlike when the enzyme is missing from birth, which causes serious heart problems.

Causal

Giving a special drug to overweight mice on a fatty diet lowers their insulin levels by 71% and helps their bodies use insulin better—without making them lose weight.

Causal

When mice eat a lot of fat and are given a special drug that blocks a fat-breaking enzyme, their livers get less inflamed and scarred—like turning down the volume on liver damage.

Causal

When scientists blocked a fat-burning enzyme in overweight mice, their belly fat dropped by three-quarters, fat in their blood fell nearly half, and their livers stored way less fat—suggesting that slowing down fat breakdown might help prevent fat from building up in the wrong places and make metabolism healthier.

Causal

Some people think taking green tea in pill form might lower your blood sugar better than drinking green tea, because the pills give you a stronger, more steady dose of the good stuff—but we’re not totally sure yet because studies don’t all agree.

Causal

Drinking green tea for less than 12 weeks might lower your blood sugar more than drinking it for longer, which suggests the benefit might fade if you keep taking it.

Quantitative

Drinking green tea supplements won’t noticeably lower your long-term blood sugar levels, even if you take them for up to a year — so it’s not a reliable way to manage diabetes or blood sugar over time.

Quantitative

Drinking green tea supplements might lower your blood sugar a bit, but it doesn’t help your body use insulin better in the short term — so your insulin levels stay about the same.

Causal

When healthy young men exercise hard at high altitudes (where there's less oxygen), their bodies release certain hormones that help break down fat and make more sugar for energy.

Mechanistic

Drinking green tea supplements for up to a year can slightly lower your fasting blood sugar by about 1.4 points — and it seems to help your body manage sugar better, not just by coincidence.

Causal

When fit young men exercise at a high altitude (like on a mountain), their body drops insulin levels way more than when they exercise at sea level—and once they stop exercising, insulin shoots back up quickly.

Quantitative

When fit young men exercise at a high altitude (like on a mountain), their bodies release more sugar, fat, and stress hormones into the blood than when they exercise at sea level—this means their body switches how it uses energy when there’s less oxygen around.

Causal

When rats have very high blood sugar (like in a dangerous condition called HHS), their fat cells don’t release as much fat into the blood — and that’s why they don’t make ketones, even though you’d expect them to.

Mechanistic

When rat fat cells are flooded with extra sugar and salt, the hormone epinephrine can’t make them release fat as well — it cuts the fat release in half.

Quantitative

When you make the environment around fat cells from rats saltier using table salt, the cells don’t break down fat as much when they’re told to by a stress hormone—but they still break down fat at the same normal rate when left alone.

Mechanistic

When you pump a lot of sugar into fat cells from a rat, a little extra sugar makes the fat-burning hormone (epinephrine) work better—but too much sugar actually shuts down that fat-burning effect.

Mechanistic

When rat fat cells are bathed in a super-sweet, salty solution, insulin doesn’t work as well to stop adrenaline from making the cells release fat — even when insulin is at normal levels.

Mechanistic

When you pump a lot of sugar and salt into the environment around fat cells from rats, those cells become less responsive to the hormone epinephrine that normally tells them to break down fat—like the hormone’s signal gets weaker.

Mechanistic