Weight Loss: Do You Really Need to Lose Weight? (cont.)
However, O'Neil believes the BMI is generally a good clinical tool for initial screening.
"The BMI is an excellent tool for helping you figure out where you are," he says. "It's a lot less useful for helping you figure out where you personally need to be."
Weight and Health
How does weight affect health? If you fall into the obese category, the evidence is pretty clear.
The April 20 Journal of the American Medical Association study reports that obesity is responsible for an estimated 112,000 deaths per year. Other studies have shown that obesity puts people at higher risk of health problems such as diabetes, heart disease, and osteoarthritis.
But even people who are obese may not need to drop much weight to improve their health.
"You don't need to lose a lot of weight in order to be healthier," says Cathy Nonas, RD, spokeswoman for the American Dietetic Association. Whether you weigh 200 pounds or 400, "the first 10% of weight that you lose ? that's the most significant improvement in your health profile that you're going to see," she says.
The Medical University of South Carolina Weight Management Center also recommends an initial loss of 10% of body weight, O'Neil says. "We know that's an amount of weight loss that can be achieved by most people."
On the contrary, Campos says he's combed the scientific literature and has found little evidence that shows weight loss is what matters with health.
"The idea that you have to be thin or so-called ideal weight in order to be healthy is just a completely bogus notion," he says. "If you compare people who have a healthy lifestyle to people with an unhealthy lifestyle, the people with the healthy lifestyle have low relative risk and the people with the unhealthy lifestyle have high relative risk, and this is true without regard to weight."
To illustrate his point, Campos refers to another study that appears in the April 20 issue of JAMA. That study showed that heart disease risk factors such as high blood pressure, high cholesterol, and smoking have declined in all BMI categories in the last 40 years.
"So-called obese people have (fewer) risk factors in terms of cardiovascular disease now than so-called ideal-weight people had 20 years ago," says Campos. He says that it's a person's lifestyle, not his or her weight, that has the most effect on health.
Williamson agrees that lifestyle is important for good health. But he says obesity remains a serious condition, even with improvements in heart disease risk factors. Those improvements don't extend to diabetes, which is linked to excess weight and which continues to increase in the general population.
The increased risk of diabetes that comes with being overweight can be improved with even small amounts of weight loss, says Nonas. She adds that being overweight can also put a strain on the joints, heart, liver, and kidneys.
Nonas casts a skeptical eye on the recent JAMA studies' findings on lower death risk for the overweight and on improvements in heart disease risk factors for the overweight and obese.
"We have of late developed all these wonderful medications which can keep a person alive and keep their cholesterol down, but it doesn't mean that they're healthy," says Nonas. "We have heart attacks and neuropathies (nerve problems caused by diabetes), and just because we can keep them alive, it doesn't mean that we can keep them alive in a way in which any of us would really want to live."
Who Should Lose Weight?
Tara Gidus, RD, a spokeswoman for the American Dietetic Association, says it's possible to be fit and fat -- and that's better than being unfit and fat. But if you're overweight, she says, you still need to lose weight.
The best time to start thinking about weight loss, says Gidus, is when you hit the BMI range of 25 to 27 -- overweight and heading into obesity.
Another expert, Vincent Pera, MD, director of the Weight Management Program at Brown University's Miriam Hospital, says the question of whether someone needs to lose weight must be determined on a case-by-case basis. That's because everyone's bodies and health profiles are different.
Also, he says, there are still a lot of unknown factors about obesity.
"We don't understand all the causes of obesity, and why it is so difficult for some people to control their weight," says Pera. "We don't understand why some people with obesity have so many problems and others don't have those problems."
Published May 5, 2005.
SOURCES: Paul Campos, law professor, University of Colorado; author, The Diet Myth: Why America's Obsession with Weight Is Hazardous to Your Health. Cathy Nonas, RD, spokeswoman, American Dietetic Association. Patrick M. O'Neil, PhD, director, Weight Management Center, Medical University of South Carolina. Tara Gidus, RD, spokeswoman, American Dietetic Association. David F. Williamson, PhD, senior epidemiologist, Diabetes Division, CDC. Vincent Pera, MD, director, Weight Management Program, Brown University's Miriam Hospital. The Journal of the American Medical Association, April 20, 2005. News release, National Institutes of Health.
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