For this latest study, researchers looked at almost 43,000 participants in the Health Survey for England and the Scottish Health Survey. Each person’s BMI and waist-to-hip ratio was compared against their health history during 10 years of follow-up.
The study participants’ average age was 58. And, just over half had central obesity. Forty-four percent were overweight. One-quarter were obese. Folks who were overweight and obese were much more likely to have central obesity than people with a normal BMI.
Researchers found that the risk posed by a big belly was the same for men and women, Stamatakis noted.
However, men are more likely to store fat around their middle, which could mean they are more likely to develop this risk, Loos said. Women tend to store fat in their hips and buttocks.
“It is indeed true that men have more of the one type of body shape, and women the other,” Loos said.
Excessive fat around the waist has been linked to insulin resistance, high cholesterol, and increased inflammation, Stamatakis said. These all are risk factors for heart disease.
A high waist-to-hip ratio also can indicate less muscle mass in the legs, which also increases heart disease risk, Stamatakis added.
“In fact, people who have high BMI often have larger amounts of fat stored in the hips and the legs, and this appears to be better for metabolic and cardiovascular health for reasons we cannot fully understand,” he said.
Loos said belly fat might be more harmful than fat stored in the hips because it more directly affects the central organs of the body.
“If you store fat around your belly and around your organs, it’s going to affect your liver function, it’s going to affect your heart function,” Loos said.
Both Stamatakis and Loos said people with belly fat should take steps to improve their health, by eating right, exercising and cutting out other risk factors like smoking or drinking.
Unfortunately, weight loss efforts will not necessarily eliminate your spare tire. Weight loss tends to occur evenly across the entire body, and cannot be directed toward any exact store of fat, Loos noted.
“There’s no way of specifically targeting that belly fat,” Loos said. “Even exercises like doing sit ups are not going to specifically help you lose fat in your belly.”
The new study was published April 24 online in the Annals of Internal Medicine.
