Obesity in children is the result of unhealthy lifestyle habits, not genes say researchers.
A study of sixth graders in Michigan, compiled by the University of Michigan Cardiovascular Center, suggests childhood obesity if fueled by unhealthy lifestyle habits, except in rare cases of extreme obesity.
In the study, obese children were found to eat foods in school cafeterias instead of packing a lunch from home and spent two hours a day in sedentary activities like watching TV and playing video games.
The researchers say leptin deficiency from gene mutation has been blamed for overeating, but according to the U-M study, lifestyle factors were closely associated with obesity rates in the children studied, ruling out heredity as the cause for the increase in number of overweight and obese children.
"For the extremely overweight child, genetic screening may be a consideration," says study senior author Kim A. Eagle, M.D., a cardiologist and a director of the U-M Cardiovascular Center. "For the rest, increasing physical activity, reducing recreational screen time and improving the nutritional value of school lunches offers great promise to begin a reversal of current childhood obesity trends."
According to information from the study, childhood obesity has increased from 6.5 percent in 1980 to 19.6 percent in 2008 among children age 6 to 11.
In the study, 41 percent of normal weight children had watched television the day before, compared to 58 percent of obese youth. Only 34 percent of non-obese children ate school lunches, compared to forty-five percent of those who were obese.
"If diets and physical activity were similar in obese and non-obese students this would argue for a stronger genetic basis for obesity in children," says study first author Taylor Eagle.
Less than half of the children in the study who are obese reported they had not eaten two servings of fruit or vegetables in the past 24 hours. Thirty percent said they drank regular soda the previous day.
Study co-author Elizabeth Jackson, M.D., assistant professor of internal medicine at the U-M Cardiovascular Center says, "It's clear that opportunities to improve health abound for the majority of our students, not just the 15 percent who are already obese."
The Healthy, Hunger-Free Kids Act of 2010, recently signed by President Obama is a proactive tool to help curb childhood obesity by bringing healthier lunches to school cafeterias. The number of obese children has tripled in the past 30 years. The new study shows lifestyle factors that include excess screen time and poor diet, not genes, seem to be the major culprits.
"Health status and behavior among middle-school children in a Midwest community: What are the underpinnings of childhood obesity?"
American Heart Journal: Vol. 160, Issue 6, December 2010. http://www.ahjonline.com/article/S0002-8703(10)00888-4/abstract