TUESDAY, Nov. 15 (HealthDay News) -- Guys with low IQs may be at higher risk than brainiacs for later weight gain and added heart disease risk, a new study suggests.

Swedish men who had the lowest IQs at about age 18 had higher waist-to-hip ratios at age 40 than their peers who scored higher on those IQ tests. It's known that people with "apple-shaped" bodies, or more weight around the middle, are at higher risk for heart disease than those with "pear-shaped" bodies.

Exactly how or even if IQ during late adolescence affects waist size is not clearly understood, and U.S cardiologists caution that it is too early to draw any meaningful conclusions from the new data. The findings are scheduled for presentation Tuesday at the American Heart Association annual meeting in Orlando, Fla.

Study author Dr. Jerzy Leppert, a professor at the Center for Clinical Research of Uppsala University in Sweden, said the message is clear. "Present strategies that aim to stop the obesity epidemic should change focus ... and concentrate more on the group most likely to benefit, i.e. those with low IQ," Leppert said.

Of 34,400 people who took part in a health survey that measured waist-to-hip ratio on or around their 40th or 50th birthday, about 5,400 men had also taken an IQ test when they were about 18. IQ tests are mandated in Sweden. Men who had the lowest IQs as older teens had the highest waist-to-hip ratios at age 40, the study showed. By contrast, those who scored highest on the IQ tests had the lowest waist-to-hip ratios at age 40.

Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York City, said if the study is validated, doctors and other health educators may need to alter their approach to prevention.

"People who have a lower IQ may be less educated and have less of an understanding about how to eat healthy," she said. "We need to educate all people, not just those who might have greater access to healthy foods and/or higher IQs."

Dr. Stephen Kopecky, a cardiologist at Mayo Clinic in Rochester, Minn., said that it is hard to say what came first -- lower IQ or wider waistlines. Some research has linked low IQs or lower education levels to lower socioeconomic status. "We do know that it can be expensive to eat properly, and if you are a single parent of two kids who is struggling to pay the bills, it is hard to stretch the dollar," he said.

Healthy foods are often more expensive and harder to come by than unhealthy foods, he noted. Certain zip codes may also have more fast food restaurants, and fewer outdoor public spaces that are safe for activity. "This is a thought-provoking study that doesn't give us all the answers," Kopecky said.

American Heart Association President Dr. Gordon F. Tomaselli agreed. "You could argue that people with a lower socioeconomic status may not be in a position to hear messages where we broadcast them," Tomaselli said.

"We have to make our messages clear and straightforward and easy to understand," he added. This may include reaching out in non-traditional ways, including social media, he said.

Research presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.

More information

For tips on how to measure waist-to-hip ratio, visit the American Heart Association.