Not everyone who is obese needs to lose weight — it's possible to carry extra pounds and still be healthy, a new study says.
Although obesity brings an increased risk of many health complications, the new study shows that people who are obese but do not have such complications might live as long as normal weight individuals.
"This illustrates that you can't have one sweeping brush to categorize all obese individuals," said study researcher Jennifer Kuk, an assistant professor at York University in Toronto. People need to look at whether they have additional risk factors indicating poor health to determine whether they should lose weight, Kuk said.
In fact, the results suggest that "yo-yo dieting," in which individuals lose weight but gain it back later, might be more unhealthful for some obese people than simply maintaining their weight, Kuk said. Participants in the study who lost the most weight over their lifetime, but hadn't necessarily kept the weight off, were more likely to have additional health complications from their obesity than those who lost less weight.
The researchers are working to develop a scaling system that could help physicians determine which obese patients would benefit from weight loss. The study was published today (Aug. 15) in the journal Applied Physiology, Nutrition and Metabolism.
Obesity and mortality
Kuk and colleagues studied the Edmonton Obesity Staging System (EOSS), which classifies obese individuals into five categories based on their health risks. Obese individuals who have no obesity-associated diseases, such as diabetes, hypertension, back pain or depression, are classified as stage 0. The more risk factors you have in addition to obesity, the higher on the scale you rank.
The researchers analyzed data from about 6,000 obese, middle-age Americans who attended a health clinic in Dallas between 1987 and 2001. The participants were assessed by a physician for health complications. They also answered questions about their physical activity level, fruit and vegetable intake and past weight loss efforts.
After 16 years, people classified as EOSS stage 2 or 3 were about 1.6 times more likely to have died of any cause, and about 2 times more likely to have died of cardiovascular disease as normal-weight individuals.
However, those classified as stage 0 or 1 were no more likely to have died than those of normal weight. In fact, stage 0 or 1 participants were less likely to die from cardiovascular disease than people of normal weight, the researchers said.
Stage 0 and 1 individuals were more likely to be physically active and eat more fruits and vegetables than those classified as stage 2 or 3. Stage 0 or 1 participants were also less likely to report engaging in weight loss practices.
Dieting may be risky to your health if you regain the weight you've lost, Kuk said. Most people who lose weight will ultimately put the pounds back on, and may regain more than they lost, she said.
Obese but healthy
It's "absolutely" possible for people to be overweight or obese and healthy, said Dr. Pieter Cohen, an assistant professor of medicine at Harvard Medical School and a general internist at Cambridge Health Alliance. However, the new study is just a "small piece in a larger puzzle," to try to determine which individuals will benefit from weight loss, Cohen said.
Even if we identify individuals at high risk for complications from obesity, it's unclear whether losing weight will reduce their risk of dying, Cohen said. To more clearly answer the question, researchers should randomly assign obese people to either lose weight or maintain their weight and practice a healthy lifestyle, to see which group sees more improvement in health, Cohen said.
The findings do not give obese individuals a "free license" to gain weight, Kuk said. Rather, the study suggests that maintaining weight, eating right and exercising may, in the long run, be better than trying to lose weight, Kuk said.
Pass it on: Some obese individuals may be better off maintain their weight and practicing a healthy lifestyle than attempting to lose weight, a study suggests.
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Rachael is a Live Science contributor, and was a former channel editor and senior writer for Live Science between 2010 and 2022. She has a master's degree in journalism from New York University's Science, Health and Environmental Reporting Program. She also holds a B.S. in molecular biology and an M.S. in biology from the University of California, San Diego. Her work has appeared in Scienceline, The Washington Post and Scientific American.