Obese children in America are much less physically active, consume larger quantities of food during school meals, and watch much more TV than their normal-weight schoolmates, researchers from the University of Michigan Medical School revealed in The American Heart Journal. Lifestyle is by far the major driving force behind childhood obesity in the USA, and not heredity, the authors stressed after examining data on check-ups of 1,003 Michigan sixth-graders in a school-based health program.
The obese children in this study tended to eat a school lunch rather than a packed one made at home, and spent a considerable amount of time either playing video games or watching television.
Senior author Kim A. Eagle, M.D., said:
"For the extremely overweight child, genetic screening may be a consideration. 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."
In a move to improve childhood health, the Healthy, Hunger-Free Kids Act of 2010 was signed by President Obama. It is aimed at creating healthier school meals. 31 million children eat at school through school programs.
The act focuses on reducing salt, sugar and fat levels in school foods to reduce obesity among children. Childhood obesity rates have more than tripled in America over the last 3 decades, from 6.5% in 1980 to 19.6% in 2008. Experts say that proportion is probably even higher now.
In a communiqué, University of Michigan Medical School wrote:
"Children involved in the study participate in Project Healthy Schools, school-based program supported by communities and the U-M Health System to teach middle school students about healthy lifestyles, in hopes of reducing their future risk of cardiovascular disease and diabetes.
Project Healthy Schools is available at 13 Michigan middle schools and is one of the few school-based programs to show sustained benefits in reducing cholesterol and high blood pressure among participants. "
58% of the obese children in the study had watched at least two hours of TV the day before, the authors reported, compared to 41% among the other kids. 34% of non-obese children ate school lunches regularly, compared to 45% of the obese ones.
Regular exercise, being a member of a school sports team, and rates of physical activity were considerably lower among the obese pupils.
Because of observed eating and physical activity habits, the researchers believe lifestyle is the driving force behind America's childhood obesity explosion, not genetics. They are not saying genetics does not play a part at all, but that genetics is not the major factor.
Leptin deficiency has been found to result in overeating. Leptin is a hormone that regulates hunger, and consequently how much we eat.
First author, Taylor Eagle, said:
"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."
All of the children in this study reported unhealthy habits, regardless of how much they weighed. 15% of the middle school students were obese.
Approximately one third of them had drunk a regular (non-diet) soda the day before. The majority of them could not remember having eaten two portions of vegetables and fruits during the previous 24-hour period.
Just one third of them had exercised for 30 minutes on five separate occasions during the previous seven days.
Co-author Elizabeth Jackson, M.D., said:
"It's clear that opportunities to improve health abound for the majority of our students, not just the 15 percent who are already obese."
"Health status and behavior among middle-school children in a midwest community: What are the underpinnings of childhood obesity?"
Taylor F. Eagle, Roopa Gurm, MS, Caren S. Goldberg, MD, Jean DuRussel-Weston, RN, MPH, Eva Kline-Rogers, RN, LaVaughn Palma-Davis, MA, Susan Aaronson, MS, Catherine M. Fitzgerald, MPH, Lindsey R. Mitchell, MPH, Bruce Rogers, Patricia Bruenger, Elizabeth A. Jackson, MD, MPH, Kim A. Eagle, MD
American Heart Journal Volume 160, Issue 6, Pages 1185-1189 (December 2010)
Written by Christian Nordqvist