Nov. 16, 2011 -- When it comes to heart and stroke risk, some of us may be able to leave our childhoods behind.
Obese children who manage to get to a healthy weight before they reach adulthood have the same risk for heart disease and other obesity-related diseases as kids who were never overweight, new research shows.
Investigators looked at information from four large studies that followed children into adulthood in an effort to determine if childhood obesity necessarily leads to an increase in heart and stroke risk as an adult.
They found little evidence of a long-term health impact associated with early obesity among adults who had been able to get back to a normal weight.
While this finding was encouraging, there was a not-so-surprising discouraging finding as well: Most obese children became obese adults, and their risk for heart attacks, stroke, and diabetes was much higher than their normal-weight counterparts.
"As far as we know this is the first time it has been shown that obesity as early as the age of 3 may not have long-term health consequences in children who are able to lose the weight before adulthood," study researcher Markus Juonala, MD, PhD, of the Turku University Hospital in Finland, tells WebMD.
"But only about 20% of obese children were normal weight as adults, compared to about 85% of children who were not overweight or obese," Juonala says. "This illustrates the importance of doing as much as we can to prevent childhood obesity."
The findings are published in The New England Journal of Medicine.
Benefits of Reaching a Healthy Weight in Childhood
Researchers examined data on about 6,300 people who took part in four studies. The study participants were followed for an average of 23 years from childhood to adulthood. Obesity was defined as having a body mass index (BMI) of 30 or greater.
Body mass index is a calculation that divides your weight by your height to estimate your amount of body fat. In children, body mass index is compared to other children the same age and sex and expressed as a percentile.
Compared to people whose weight was normal over the entire time of the studies, those who remained obese from childhood to adulthood had a fivefold greater risk for developing type 2 diabetes. They also had a nearly threefold greater risk for developing high blood pressure and a twofold greater risk for having low HDL "good" cholesterol.
Obese children who became obese adults also had nearly two times the risk for plaque buildup in the neck arteries -- a major cause of stroke.
For most of these outcomes, study participants who were obese during childhood but normal weight as adults had a risk similar to participants who were never obese.
Olli T. Raitakari, MD, who was the review's senior researcher, says it is significant that the findings were similar across all four studies, which were conducted in Europe, Australia, and the U.S.
He says the findings highlight the importance of making the prevention of childhood obesity a top public health goal.
"Once children become obese they have a very high risk for becoming obese adults," he tells WebMD. "From a public health standpoint, we would derive the most benefit from preventing obesity rather than treating it."