Losing excess weight in childhood cuts risk for diabetes

If an overweight child slims down before puberty, the risk of type 2 diabetes seems to slide away with the lost pounds.

Later weight loss also lowers the risk of type 2 diabetes in adulthood, just not as much, new research reports.

"The sooner we can get children to a healthy weight and lifestyle, the better off they'll be," said nutritionist Samantha Heller from NYU Langone Health System in New York City. Heller wasn't involved in the current study, but reviewed its findings.

Nearly one-quarter of the world's children are overweight or obese, the researchers pointed out in the study.

The study's lead author, Lise Bjerregaard, said it's known that being overweight in childhood and early adulthood is linked to a higher risk of type 2 diabetes later in life. The researchers wanted to know if diabetes risk would change if overweight kids lost weight.

"We studied the associations between different combinations of weight status in childhood, adolescence and early adulthood, and later development of type 2 diabetes," said Bjerregaard. She is a postdoctoral research fellow at Bispebjerg and Frederiksberg Hospital in Denmark.

The study included data from almost 63,000 men living in Denmark. Each had their weight and height measured at ages 7 and 13 years, and again in early adulthood (between 17 and 26 years old).

The researchers also collected information on whether or not type 2 diabetes was diagnosed when these same men were between 30 and 60 years old.

If kids who were overweight at 7 years old lost weight before age 13, their risk of developing type 2 diabetes in adulthood dropped to the same level as someone who had never been overweight, the findings showed.

And when an overweight child lost weight before adulthood, but not before puberty, the odds of developing type 2 diabetes in adulthood were nearly 50 percent higher than someone who had always been at a normal weight.

However, they were significantly less likely to develop type 2 diabetes than someone who stayed overweight from childhood into early adulthood, the researchers said. Someone who stayed overweight throughout childhood and early adulthood had more than four times higher odds of developing type 2 diabetes as an adult than someone who'd always been a normal weight.

Youngsters who were slim at age 7, but gained excess weight by early adulthood also increased their risk of type 2 diabetes, the investigators found.

The researchers noted that although the exact risk levels might vary, they expect that different populations -- say, people in another country -- would likely see a similar reduction in the risk of adult type 2 diabetes with earlier weight loss.

Heller explained that when someone loses weight, they become less insulin resistant and the body's metabolism works more efficiently.

"The body becomes more efficient at burning fat, and there's less inflammation," she said.

Endocrinologist Dr. Andrea Dunaif, from the Icahn School of Medicine at Mount Sinai in New York City, also reviewed the study's findings.

"These findings suggest that the adverse effects of childhood overweight can be reversed by normalizing weight prior to puberty," she said. "In contrast, the adverse effects of overweight on diabetes risk at puberty and older are only partially reversible."

Dunaif added that these findings suggest that weight-loss interventions should target overweight children before puberty, and then emphasize weight maintenance.

Heller said parents can help their children by acting as role models.

"Model healthy eating. It's hard when you're tired after a day of work not to go to the drive-thru or to throw in a frozen pizza, but the long-term consequences aren't worth it. If kids get used to fast-food and junk foods and soda that are highly palatable, that's setting them up for a very difficult life of trying to make healthier choices later on," Heller explained.

"Eat healthier, engage in physical activity, get them outside playing. Make these changes now, and maybe you can save them from diabetes later," she advised.

The study was published in the April 5 issue of the New England Journal of Medicine.

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