Surprise: Everyone has some belly fat, even people who have flat abs. That's normal. But too much belly fat can affect your health in a way that other fat doesn't. Some of your fat is right under your skin . Other fat is deeper inside, around your heart , lungs , liver , and other organs. It's that deeper fat -- called " visceral " fat -- that may be the bigger problem, even for thin people. Deep Belly Fat You need some visceral fat . It provides cushioning around your organs. But if you have too much of it, you may be more likely to get high blood pressure , type 2 diabetes , heart disease , dementia , and certain cancers, including breast cancer and colon cancer . The fat doesn't just sit there. It's an active part of your body, making "lots of nasty substances," says Kristen Hairston, MD, assistant professor of endocrinology and metabolism at Wake Forest School of Medicine. If you gain too much wei