Small Weight Loss Leads to Big Health Gains

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Losing just 5 percent of your body weight can have significant positive effects on your health, a new small study finds.

In the study, people who lost 5 percent of their body weight were found to have improvements in several risk factors for heart disease and type 2 diabetes, including how well their bodies reacted to the hormone insulin, and how well certain cells in the pancreas functioned. (Insulin resistance, a condition in which the body cells do not respond properly to insulin, increases a person's risk for both heart disease and type 2 diabetes.)

"Our findings show that even a small amount of weight loss has important health benefits for multiple organ systems," Dr. Samuel Klein, a professor of medicine and nutritional science at Washington University School of Medicine in St. Louis and the senior author on the study, said in a statement.  [The Best Ways to Lose Weight Safely]

And the greater the weight loss, the greater the health benefits. Not only did insulin sensitivity improve even more with greater weight loss among the people in the study, but the researchers also observed other benefits, including decreased levels of inflammation in the body, the researchers wrote in their findings, published today (Feb. 22) in the journal Cell Press.

In the study, 40 obese people were randomly assigned to either a weight loss program or a weight maintenance program. All of the participants underwent baseline testing before starting on their assigned programs. Of the 20 people in the weight loss program, all were required to lose 5 percent of their body weight. Then, 10 of these participants were assigned to continue losing weight, with the goal of eventually losing 15 percent of their body weight, the study said.

The researchers found that the participants who lost 5 percent of their body weight had improved insulin sensitivity, lower systolic blood pressure and lower levels of triglycerides (a type of fat linked to heart disease) in their blood.

Moreover, all of these improvements were seen, and were progressively larger, in the participants who lost more than 5 percent of their weight. The group that aimed to lose 10 percent had slightly more dramatic improvements, and the group that aimed to lose 15 percent fared even better, the study said.

In addition, greater weight loss was associated with decreased inflammation as well as signs of a better ability to fight oxidative stress, which can damage cells, the study said.

Currently, several major medical and government organizations, including the American Heart Association and the Centers for Disease Control and Prevention, recommend weight loss of 5 to 10 percent of a person's body weight for people who are obese. However, no studies have focused specifically on the effects of losing 5 percent of a person's body weight, the study said.

"Based on these findings, we should reconsider changing the current obesity practice guidelines to stress a target goal of 5 percent weight loss, rather than 5 percent to 10 percent weight loss, which increases the perception of failure when patients do not achieve weight losses that are greater than 5 percent," Klein said.

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Sara G. Miller
Staff Writer
Sara is a staff writer for Live Science, covering health. She grew up outside of Philadelphia and studied biology at Hamilton College in upstate New York. When she's not writing, she can be found at the library, checking out a big stack of books.