Those extra pounds you've been meaning to shed may be hurting more than just your vanity. In fact, losing weight now may help you live longer. A recent study -- the largest yet on obesity and mortality -- has found that the more overweight you are, the higher your risk of death. The results, based on data from more than one million adults and published in The New England Journal of Medicine, held true for all age groups and even for those who were disease-free and had never smoked.
"As a society, we're getting heavier and heavier, and there's a cost associated with it in terms of our health," says the study's lead author, Eugenia E. Calle, PhD, the director of analytic epidemiology at the American Cancer Society's department of epidemiology and surveillance research in Atlanta, Georgia. Obesity rates in this country have increased from 12% in 1991 to 18% in 1998, according to another study published earlier this year in the Journal of the American Medical Association (JAMA).
While death rates from all diseases increased with the number of excess pounds, Calle and her co-researchers found that certain diseases had particularly strong associations with obesity. The heaviest participants had a 40 to 80% higher risk of dying from cancer than participants of normal weight. Extra pounds put both men and women at higher risk for heart disease -- but in men the added risk was particularly striking: The heaviest men were three times more likely to die from heart disease than men of normal weight.
Researchers followed participants for 14 years, from 1982 to 1996. The average age at enrollment was 57 years. Based on weight and height information provided by the study subjects, researchers calculated their body-mass indexes (the weight in kilograms divided by the square of the height in meters). The study considered a normal BMI to be between 18.5 and 24.9, a range set by the World Health Organization.
By way of comparison, currently 20% of Americans have a BMI of 30 or more, which is defined as obese. A 5'5" person who weighs 180 pounds, for example, has a BMI of 30. Men with the highest BMIs who were disease-free and nonsmokers nevertheless were more than two and a half times as likely to die during the study period as those with normal BMIs. The heaviest women were almost twice as likely to die as the thinner women.
Age and Weight
Researchers found that the risk from obesity lessened with age. But being overweight still increased the subjects' risk of death from all causes in all stages of life. The study clearly shows, says Calle, that it's important to maintain a healthy weight throughout your entire life.
Obesity not only increases your risk of dying, but can also affect the quality of your life when you're older, says David F. Williamson, a senior biomedical research scientist at the Centers for Disease Control and Prevention in Atlanta. "It's harder for you to get out of a chair if you're obese," he says, "or to walk to your bed without your knees hurting or to play with your grandchildren."
The best way to achieve a healthy weight, says Calle, is a combination of exercise and smart eating.
The American Cancer Society recommends you:
- Choose most of your foods from plant sources, including five or more servings each day of fruits and vegetables.
- Limit high-fat foods, especially those of animal origin such as red meat.
- Exercise moderately for at least half an hour on most days. (And an hour would be better, according to researchers from Brown University who presented their findings at the 1999 meeting of the North American Association for the Study of Obesity. They evaluated the success of 2,500 people who lost an average of 60 pounds and kept it off, and found most exercised an hour a day.)
- Limit your consumption of alcohol.