Browse evidence-based analysis of health-related claims and assertions
Eating fewer calories for a month helps obese women lose weight and shrink their waist, but doesn’t yet reduce the deep belly fat or the fat under the skin — that takes longer, like with metformin.
Descriptive
Even women without PCOS who are obese and take metformin with a diet lose weight and belly fat, and their SHBG (a hormone that binds male hormones) goes up — but their male hormone levels don’t drop like in women with PCOS.
Causal
For obese women with PCOS, taking metformin along with a low-calorie diet helps them lose more weight, shrink belly fat, lower male hormone levels, and get more regular periods than just dieting alone.
Having diabetes and having high visceral fat (measured by VAI) each add their own separate risk for heart problems in people with heart disease — knowing one doesn’t tell you everything about the other.
Correlational
People with heart disease who also have type 2 diabetes are about 55% more likely to have a heart attack, stroke, or die from heart problems than those without diabetes — even when you account for other risk factors like weight and cholesterol.
People with heart disease who have more fat around their organs (measured by a simple formula using waist size and blood fats) are more likely to have serious heart problems like heart attacks or strokes, whether or not they have diabetes.
In people with obesity, the levels of receptors and enzymes for male and female hormones in fat tissue don’t seem to be linked to how much fat they have or where it’s stored.
In people with obesity, fat tissue that processes male hormones differently seems to be linked to having more fat around the waist.
In people with obesity, fat tissue that makes more estrogen seems to be linked to having more total body fat.
Some scientists thought that fat around the organs might make too much of the stress hormone cortisol locally, which could make people gain weight—but after looking at many studies, it seems this probably isn’t a big reason for obesity.
Losing weight—whether by eating better, exercising, taking medicine, or having weight-loss surgery—can help reduce fat, inflammation, and scarring in the liver of obese people with fatty liver disease.
Most people with fatty liver don’t feel sick, and their liver blood tests are often normal—so doctors can’t rely on symptoms or routine blood work to find it; they need imaging or to check for obesity and diabetes instead.
People with fatty liver and obesity have high levels of a hormone called leptin, but their bodies don’t respond to it properly—so it can’t stop the liver from storing fat or getting scarred.
Mechanistic
People with fatty liver have less of a helpful hormone called adiponectin, which normally helps burn fat and improve insulin sensitivity—so low levels may make their liver disease worse.
Too much fat released from belly fat or made by the liver itself clogs liver cells, triggers inflammation, and makes the liver less responsive to insulin.
Fat around the belly (visceral fat) is worse for your liver and metabolism than just being overweight overall—because it dumps harmful fats and chemicals straight into your liver.
If you use the same weight and do the same number of reps, it doesn't matter if you curl with your arm in front or behind you — what matters is just doing it consistently and getting stronger over time.
If you do the same amount of work with your arm in front or behind you, you'll get just as strong at lifting heavy weights — the position doesn't matter.
The muscle underneath your bicep gets just as strong and big whether you curl with your arm in front or behind you.
Your bicep doesn't grow more at the top, middle, or bottom no matter how you do the curl — it grows evenly all along its length.
Doing bicep curls with your arm in front of your body or behind your body gives you the same muscle growth and strength gains if you're using the same amount of weight and doing the same number of reps.
Scientists are trying to figure out why belly fat affects the liver more than fat under the skin, by comparing how the two types of fat work.
Fat around the organs dumps fat and inflammatory signals straight into the liver through a special blood pipe, where they can mess with liver cells and immune cells.
Too much fat around the organs can mess up blood sugar and fat levels in the blood, which over time can lead to diabetes and heart problems.