Scientists can create special diets for overweight men where they change how quickly carbs raise blood sugar—without changing how many calories, fiber, or fats are in the food—so they can see if the type of carb itself affects health.

You can change how quickly foods raise your blood sugar (by picking different carbs) without changing how many calories you eat or how much protein, fat, or fiber is in your diet—and this might affect health risks like insulin resistance in overweight men.

Eating foods with different sugar impacts doesn't seem to reliably change heart disease risk markers in overweight men after just four weeks—so short-term diet changes might not be enough to make a difference.

Eating either high-sugar or low-sugar carbs for four weeks doesn’t reliably change insulin response, swelling, or blood clotting in overweight or obese men—even though the types of carbs were very different.

If overweight men eat mostly high-sugar, refined carbs for four weeks, they might lose a tiny bit more fat and gain a tiny bit more muscle than if they ate whole grains and low-sugar foods—but the difference is so small that it probably doesn’t matter much for their health.

If you eat different kinds of food for four weeks—some high in sugar, some low—but everything else stays the same, your body’s insulin response, inflammation, and blood clotting don’t consistently change if you’re overweight or obese.