Weight Management

Surprising Connections
on Why We’re Obese

We've all heard warnings, yet many of us keep gaining weight. More than half of American adults are overweight or obese, says the Centers for Disease Control and Prevention (CDC).

"Obesity is an epidemic right now. This is an important public health issue that is second only to tobacco," says William H. Dietz, M.D., Ph.D., director of the CDC Division of Nutrition and Physical Activity. In general, he says, "A man who is 6 feet and weighs over 220 pounds and a woman who is 5 foot 4 and weighs over 175 pounds are considered obese."

A person who is overweight has a body mass index (BMI) of 25.0 to 29.9. Someone who is obese has a BMI of 30.0 or more.

You may know that obesity is linked to high blood pressure, diabetes, stroke, arthritis and harmful cholesterol. But scientists have five new findings you may not know:

Finding 1: Obesity can raise some cancer risks
Too much weight gain has been linked to cancers of the breast (after menopause), colon, kidney, prostate, cervix, ovary, gallbladder, liver, rectum, esophagus and uterus. The World Health Organization's International Agency for Research on Cancer (IARC) estimates at least a third of these cancers are tied to obesity. And National Cancer Institute (NCI) researchers found the obese have a 72 percent higher risk of pancreatic cancer. The NCI showed that obese people could halve their pancreatic cancer risk through exercise. IARC researchers suspect weight loss may cut the risk of the other cancers, but they're still seeking proof.

Finding 2: Obesity is tied to heart attacks in the young
Obesity has been linked to a rise in fatal heart attacks in young people. In people ages 15 to 34, the CDC notes, the death rate from heart attacks rose 32 percent among women and 10 percent among men during the '90s.

"This increase was found to be related to obesity," says Dr. Dietz. Other factors, such as smoking and drug abuse, may also play a part. The CDC says young people can often avoid such deaths through good diet and exercise habits.

Finding 3: Obesity can ruin your day
For those who are obese, daily life itself is harder, studies show.

Simple tasks like carrying groceries, walking up stairs, kneeling and stooping are harder for the obese. Research by the RAND Institute, the University of Wisconsin and the Dutch National Institute of Public Health and the Environment has shown that obese people fare worse in physical function, vitality and self-image. Sleep apnea, which is more prevalent among obese people, is often a cause of lethargy.

Obese people are also more likely to have a chronic disease or osteoarthritis. And doctors at the Glasgow Royal Infirmary in Scotland found obese women were more likely to miss work, see a doctor and feel down in the dumps than women who aren't obese.

Finding 4: Obesity speeds up girls' puberty
A study published in the journal Pediatrics found that girls who develop breasts and pubic hair earlier than their peers -- at age 8 or 9 -- tend to weigh too much.

"Girls who show signs of early puberty are at risk for behavior and emotional problems. This is just one more consequence of being overweight," says study lead author Paul Kaplowitz, M.D., associate professor of pediatrics at Virginia Commonwealth University School of Medicine.

Still, he warns, "It is hard to show cause and effect here."

Finding 5: Obesity fuels diabetes in kids
Doctors believe rising childhood obesity helps explain a sharp increase in type 2 diabetes among kids.

"The best data demonstrate that type 2 diabetes, which was a rare disease in children and teenagers, is now much more common," Dr. Dietz says. In type 2 diabetes, the body can't make enough insulin or use it properly. In 1990, fewer than 4 percent of childhood diabetes cases were type 2. Today, type 2 diabetes accounts for about 20 percent of childhood diabetes, says the American Academy of Pediatrics (AAP). Among some minorities and in some age groups, the rate is even higher.

The AAP says 85 percent of children with type 2 diabetes are obese. The disease usually turns up in middle to late puberty. Children who get little exercise, eat too much and have a family history of diabetes are at highest risk.

These researchers sound a joint theme: If you're obese, stop gaining weight and start losing.

Doctors believe dropping 5 to 10 percent of your body weight can improve your health and decrease your risk of type 2 diabetes. Before you start a weight loss program, though, talk with your doctor.

"People care about their health," says Dr. Dietz, "so it is just a matter of time before they take the necessary steps to control their weight."

About This Article
Publication: Health & You; Publication Date: Spring 2002; Author: Marianne Aleardi; Source: Centers for Disease Control and Prevention; Source URL: http://www.cdc.gov/nchs/; Online Editor: Dianna Sinovic; Online Medical Reviewer: Cynthia Godsey, M.S.N., F.N.P./C., Gordon Lambert, M.D.; Date Last Modified: 4/21/04