Why does "belly fat" specifically affect heart disease?
We know that obesity is associated with an increased risk of coronary artery disease. But it's a particular kind of obesity. It's the kind where you carry the fat and carry the weight in and around the abdomen. The reason for that is that that kind of abdominal obesity is associated with fat around the organs. It's unlike the fat that people have--we call pear-shaped--who have the fat around the buttocks and hips. That's not quite as much of a risk factor. But abdominal obesity means that if you took the heart and you looked at the heart, what you'd find is that it was actually, the coronary arteries are actually outlined in fat, so that over each blood vessel you'd see a big chunk of fat lying around the heart. And there appears to be something about having the fat there as, as opposed to having it distribted under the skin around the rest of the body that really raises your risk. We don't know quite why that is, but we know it's there. You can see that because if the fat increases in the abdomen, the belly's going to expand. If the fat increases in the chest, it can't expand because we have ribs that keep it fixed. So abdominal obesity is the important, is the important kind to look for. And we think it's important for people to keep their waist circumference under 40 inches for men and under 35 inches for women to not be in that category of higher risk.
