America's Youth is under the attack of an enemy that will cause them to live 10 years less than their parents on average. Here is a look at that problem; obesity.
BERKELEY — Location is everything - and that goes for fast food as well as for real estate.
California's nearly 3 million 9th graders are at least 5.2 percent more likely to be obese if there is a fast food restaurant within a tenth of a mile of their school, according to a new study by University of California, Berkeley, economists who calculated that these students eat 30 to 100 more calories per school day than their non-obese counterparts.
But they found no connection between fast food and obesity if the outlets are a quarter-mile to half a mile from high schools, and no correlation between obesity and the presence of non-fast-food restaurants near a school, indicating their findings reflect more than simple increases in local demand for restaurants in general. Their accompanying analysis of weight gain by pregnant mothers and their proximity to fast food outlets showed a much smaller impact for the moms than for the students.
"Our results imply that policies restricting access to fast food near schools could have significant effects on obesity among school children, but similar policies restricting the availability of fast food in residential areas are unlikely to have large effects on adults," their report concluded, noting that transportation limits on youths may be a factor.
Obesity among children ages 6-19 in the United States increased from about 5 percent in the early 1970s to a whopping16 percent in 1999-2002, and the number of fast food restaurants doubled in the same period.
Economists Stefano DellaVigna and Enrico Moretti of UC Berkeley, economist Janet Currie of Columbia University and economist Vikram Pathania, who recently earned his Ph.D. from UC Berkeley - say their work may help guide cities interested in fighting obesity to establish zoning regulations that control how close fast food outlets are placed to schools.
"If you look out the window from your classroom and see a fast food place, it's kind of tempting to go over there," said DellaVigna.
In "The Effect of Fast Food Restaurants on Obesity," just published by the National Bureau of Economic Research (NBER), the economists serve up evidence of the link between fast food availability and obesity. To date, that link has been a matter of speculation, estimation and studies using data sets too small in scale to provide much validity or precision.
They also found that while just 7 percent of California's high schools have a fast food restaurant within a tenth of a mile, 65 percent have one within half a mile. Schools within a tenth of a mile of a fast food restaurant have more Hispanic students, slightly more students eligible for free lunches, lower test scores, tend to be in poorer and urban neighborhoods - and have a higher than average incidence of obesity among their students, according to the study.
"This is a step in the direction of understanding the puzzle of obesity," said DellaVigna.
"The results ... are consistent with a model in which access to fast foods increases obesity by lowering food prices or by tempting consumers with self-control problems," the report said.
And while the current weak economy may slow the near-term expansion of fast food operations, many experts expect most fast food firms will follow McDonald's, reporting hefty earnings as cash-strapped consumers seek out cheap eats.
The economists in the NBER study used a detailed dataset showing the exact geographic location of restaurants belonging to the top 10 fast food chains, independent pizza and burger restaurants and non-fast food outlets.
They also examined records of California's 9th graders for nearly a decade (1999 and 2001-2007), tapping into a wealth of fitness facts about the students who - like their counterparts in 5th and 7th grade - must take a physical exam in the spring. Ninth graders are tested for acceptable levels of aerobic capacity and upper body and abdominal strength, and undergo body fat measurements that indicate obesity.
That information was merged with data such a school's racial mix and the percentage of its students who qualify for free lunches collected by the National Center for Education Statistics and 2000 Census data about family earnings, education and employment. This data helped control for special characteristics of schools and neighborhoods, such as the higher rates of obesity for Hispanic and black youths.
As another control, the economists used 15 years of information from the U.S. National Vital Statistics from Michigan, Texas and New Jersey recording weight gains during pregnancy for more than 1 million women with at least two children.
They found a 2.5 percent increase in obesity rates for these women - especially African Americans and those with a high school education - when fast food was available within half a mile of their homes, but there was no significant difference in rates when the outlets were a tenth of a mile or half a mile away.
Their report can be found online at:http://www.econ.berkeley.edu/~sdellavi/wp/fastfoodJan09.pdf.
• Approximately 300,000 adult deaths in the United States each year are attributable to unhealthy dietary habits and physical inactivity or sedentary behavior. ?
• Nearly two-thirds of U.S. adults are overweight (BMI > 25, which includes those who are obese).?
• Nearly one-third of U.S. adults are obese (BMI > 30).?
• The prevalence of overweight and obesity has steadily increased over the years among genders, all ages, all racial/ethnic groups, and all educational levels.?
• Approximately 19% of children (ages 6–11) and 17% of adolescents (ages 12–19) were overweight in 2000. An additional 15% of children and adolescents were at risk for overweight (based on BMI / body mass index measures).??An estimated 70 percent of diabetes risk in the U.S. can be attributed to excess weight.?
• Americans spend $33 billion annually on weight-loss products and services.?
• The cost of obesity to individuals families: It will cost approximately $549,907 for an obese 18 year old to remain obese throughout adulthood. ?
• About 25 percent of young people (ages 12–21 years) participate in light to moderate activity (e.g., walking, bicycling) nearly every day. About 50 percent regularly engage in vigorous physical activity. Approximately 25 percent report no vigorous physical activity, and 14 percent report no recent vigorous or light to moderate physical activity.?
• The percentage of children and adolescents who are defined as overweight has more than doubled since the early 1970s. ?
• In 1999-2000, over 10 percent of younger preschool children between ages 2 and 5 are overweight, up from 7 percent in 1994
Overweight: Overweight refers to an excess of body weight compared to set standards. The excess weight may come from muscle, bone, fat, and/or body water. Individuals with a BMI of 25 to 29.9 are considered overweight.??
Obesity: Obesity refers specifically to having an abnormally high proportion of body fat. Individuals with a BMI of 30 or more are considered obese.??
BMI or body mass index: A number of methods are used to determine if someone is overweight or obese. Some are based on the relation between height and weight; others are based on measurements of body fat. The most commonly used method today is body mass index (BMI).??BMI or body mass index is found by dividing a person’s weight in kilograms by height in meters squared. The mathematical formula is: weight (kg) / height squared (m²). To determine BMI using pounds and inches, multiply your weight in pounds by 704.5,* then divide the result by your height in inches, and divide that result by your height in inches a second time.