For years, scientists have known that a big belly is a health risk, but now they know why.  They have discovered that people with wide girths have large amounts of deep-hidden belly fat around their organs called visceral fat and that this type of fat could increase a person’s risk of diabetes, heart disease, stroke and some types of cancer as well as being linked to high cholesterol, high triglycerides, high blood pressure and other problems.

And because most people in the U.S. weigh too much and carry too much belly fat around, scientists are racing to find out how to reduce this killer fat.  So far, physical activity and weight loss seem to be the answer.  Several new studies indicate that walking briskly for 30 to 45 minutes a day can significantly decrease such fat.

At greatest risk of developing health problems from too much hidden belly fat are men whose waists are wider than 40 inches and women whose are wider than 35 inches.  People with waists that wide need to reduce them immediately, says Robert Ross, an exercise physiologist at Queen’s University in Kingston, Ontario. 

“We can’t keep stuffing our faces with fat and take a little stroll and think we are doing ourselves any good,” says George Blackburn, associate director of the division of nutrition at Harvard Medical School.  People have to walk briskly and break a sweat, he says.  They need to be active for 60 minutes a day.  And they have to cut back on junk food, he says.