If you’re overweight or obese, shedding a few pounds — even as little as 5 to 10 percent of your body weight — is likely to lower your risk of developing medical conditions like heart disease, stroke and diabetes.
That’s been the message of health organizations, including the Centers for Disease Control and Prevention (CDC) and the American Heart Association (AHA), for many years.
It’s been unclear, however, whether higher levels of weight loss — beyond 10 percent — might result in incrementally better health results for people carrying around excess pounds.
A new study, published last week in the journal Mayo Clinical Proceedings, suggests it may. The study found that overweight and obese people who lost more than 20 percent of their body weight were almost 2½ times more likely to have good metabolic health as those who lost 5 to 10 percent.
“If you’re overweight or obese, even losing just a little is better than none,” said Gregory Knell, the study’s lead author and a postdoctoral researcher at the University of Texas, in a released statement. “But the rewards appear to be greater for those who manage to lose more.”
Almost 40 percent of adults in the United States are obese, and another 30 percent are overweight, according to the CDC. Those numbers are expected to rise over the next decade, with immense health consequences. Obesity is a major risk factor for a host of chronic medical conditions, including not just heart disease, stroke and type 2 diabetes, but also osteoarthritis, fibromyalgia, joint problems, gallstones and certain types of cancer.
For the current study, Knell and his co-authors used data collected from 7,670 Americans, aged 20 to 64, who participated in the National Health and Examination Survey (NHANES) between 2007 and 2014. All of them had a history of being overweight or obese — and a history of attempting to lose weight. The data include information about that weight history, as well as results from physical examinations.
With that information, the researchers were able to identify the participants with metabolic syndrome, which is defined by the AHA (and this study) has having three or more of the following: a high waist-to-hip circumference, high triglycerides, high blood pressure, high blood sugar, and low HDL (the so-called good cholesterol).
People with metabolic syndrome are at increased risk for various health problems, particularly heart disease, stroke and type 2 diabetes.
The researchers then looked to see if there was an association between long-term weight loss (lasting at least 12 months) and the risk of developing metabolic syndrome. They found that compared to the participants who had lost less than 5 percent of their weight, those who had lost between 5 and 10 percent were 22 percent less likely to have metabolic syndrome.
But the reduction in risk was even greater for those who had lost more than 20 percent of their weight. They were 53 percent less likely to have metabolic syndrome.
Unfortunately, the study’s findings also underscore the tremendous struggle that Americans have with losing weight. Despite trying, two-thirds (62 percent) of the study’s participants were unable to lose even 5 percent of their excess weight.
And only about one in 20 (5.5 percent) of the people in the study succeeded in losing 20 percent or more of their weight.
Limitations and implications
The study was observational, so its findings shouldn’t be interpreted as showing a direct causal relationship between the percentage of lost body weight and the likelihood of having metabolic syndrome. Other factors, not identified in this study, may explain that correlation.
Also, the participants self-reported their history of weight loss, and such reports may or may not be accurate.
At a minimum, however, the study’s findings support the current health recommendations that people who are overweight or obese try to shed at least 5 to 10 percent of their excess weight.
“Since weight loss is so difficult, a 5 to 10 percent weight loss for those with excess weight should be the target,” said Knell. “This should be done gradually through following a healthy lifestyle with guidance from experts, such as your primary care provider.”
But if you can lose more — according to this study, at least — so much the better.
FMI: You’ll find the study online at the Mayo Clinical Proceedings website.