A 5 percent weight loss can dramatically improve health.
Obese folks trying to lose weight can focus on smaller goals. A new study shows the biggest health benefits come from losing just 5 percent of their body weight. In fact, this relatively small weight loss significantly lowers a person’s risk for heart disease and diabetes and improves metabolic function in liver, fat and muscle tissue.
“Our findings demonstrate that you get the biggest bang for your buck with 5 percent weight loss,” says lead investigator Samuel Klein, professor of medicine and nutritional science at Washington University in St. Louis. “The current guidelines for treating obesity recommend a 5 to 10 percent weight loss, but losing 5 percent of your body weight is much easier than losing 10 percent. So it may make sense for patients to aim at the easier target.”
For the study, researchers randomly assigned 40 obese individuals — none of whom had diabetes — either to maintain their body weight or go on a diet to lose 5, 10 or 15 percent of body weight. Previous randomized clinical trials have analyzed the effects of varying weight loss in obese people, but this is believed to be the first time a trial has separated weight loss outcomes in people who achieved a 5 percent weight loss from those who achieved a 10 percent or greater weight loss.
Nineteen study participants who lost 5 percent of their body weight saw improved function of insulin-secreting beta cells, as well as insulin sensitivity in fat tissue, liver and skeletal muscle tissue. A 5 percent weight loss also was associated with decreases in total body fat and less fat in the liver. Nine of those study patients continued to lose weight, eventually reaching 15 percent weight loss, experiencing further improvements in beta cell function and insulin sensitivity in muscle tissue, but neither insulin sensitivity in the liver nor fat tissue continued to improve with the greater weight loss.
“Continued weight loss is good, but not all organ systems respond the same way,” Klein said. “Muscle tissue responds much more to continued weight loss, but liver and adipose tissue have pretty much achieved their maximum benefit at 5 percent weight loss.”
Of note: In the study, markers of inflammation, which are elevated in obese people, didn’t change much when study participants lost a moderate amount of weight. Scientists hypothesize that increased inflammation in fat tissue contributes to metabolic issues, such as insulin resistance, but the new study shows metabolic function could improve while markers of inflammation remain unchanged.
That part of the research requires further study. Klein said the study also needs to expand to include people who have diabetes. “We don’t know whether people with diabetes will have the same response to this type of progressive weight loss, so it will be important in the future to repeat this type of study in people who have type 2 diabetes.”
Meanwhile, people with obesity can improve their health significantly by losing even a small amount of weight. “If you weigh 200 pounds, you will be doing yourself a favor if you can lose 10 pounds and keep it off,” Klein said. “You don’t have to lose 50 pounds to get important health benefits.”
This is welcome news for African-American women, who carry the biggest obesity burden of all the populations in the United States.