When overweight mice eat fewer calories, only those on a low-carb, high-fat diet see a big drop in blood fats called triglycerides — other diets don’t have the same effect.

When overweight mice eat significantly less food, they lose body fat no matter if their diet is low in carbs, low in fat, or high in protein — the key is eating fewer calories overall.

When overweight mice lose weight by eating less, their cholesterol levels go down — no matter what kind of food they eat — because the drop in cholesterol is tied to how much weight they lost.

In mice on a high-fat diet, repeatedly losing and regaining weight through calorie restriction does not worsen key metabolic markers such as blood sugar, fat levels in the blood, or body fat compared to mice that maintain a stable weight.

Almost everyone who switched to a low-fat, high-carb diet saw their blood fat levels go up—only one person didn’t, which means this effect happens in nearly all people.

When overweight mice eat fewer calories, their blood sugar control gets better — but if their diet is very low in carbs, their blood sugar doesn’t improve as much as if they ate more carbs.