A diet that’s low in fat and carbohydrates can improve artery function, according to a 2012 study by Johns Hopkins researchers. After six months, those on the low-carb diet had lost more weight, and at a faster pace. But in both groups, when weight was lost—and especially when belly fat shrank—the arteries were able to expand better, allowing blood to travel more freely. The study shows that you don’t have to cut out all dietary fat to shrink belly fat. For heart health, simply losing weight and exercising seems to be key.