Health Risks
Insufficient Physical Activity
The American Academy of Pediatrics notes that children in the United States spend about four hours in front of the television every day and children who watch too much television are more likely to be overweight.[22]
The U.S. Department of Health and Human Services recommends at least 60 minutes of physical activity for children on most, preferably all, days of the week.[17] For children and adolescents, this regular physical activity helps build and maintain healthy bones and muscles, reduces the risk of developing obesity and chronic diseases, reduces feelings of depression and anxiety, and promotes psychological well-being.[18]
Despite these benefits, many children are not getting adequate physical activity. The Centers for Disease Control and Prevention (CDC) report that of children ages 9 to 13 years, 62 percent do not participate in any organized physical activity and 23 percent do not engage in any free-time physical activity outside of school hours.[19] During the school day, only 8 percent of elementary schools and 6 percent of middle/junior high schools provide daily physical education classes, and recess is no longer provided in some elementary schools.[20] Unfortunately, less active children are more likely to be overweight, according to the American Academy of Pediatrics.[21]
Overweight and Obesity on the Rise
When it comes to children’s health, the costs of inadequate physical activity and poor eating habits are alarming. Inadequate physical activity and poor eating habits are major contributors to the increased rates of childhood obesity and overweight in the United States. Obese children are at least twice as likely to become obese adults. This puts obese children at greater risk for premature death and chronic diseases than their healthy weight counterparts.[25], [21] Public health and medical professionals have begun to speculate that the current generation of children may be the first that will not live as long as their parents.[26], [27]
The following chart, using data from the National Health and Nutrition Examination Survey (NHANES), shows the proportion of American children in two age groups whose weight is higher than the 95th percentile of the recommended weight for their height.[28] The percentage of 6 to 11 year-old and 12 to 19 year-old children who are considered severely overweight tripled in the last 30 years. Even among the youngest children, ages 2 to 6, the rate of being severely overweight has doubled.[29]
Source: CDC/National Center for Health Statistics, National Health Examination Survey and NHANES
The negative health consequences of overweight and obesity include premature death and chronic diseases, such as diabetes, heart disease, high blood pressure, asthma and various cancer types. [30], [31] Other impacts include increased health care costs, lost productivity and social stigmatization.[30], [32] During childhood, many obese individuals experience social stigmas and discrimination, which are believed to lead to a high incidence of low self-esteem and symptoms of depression.[33] For obese children between 5 and 10 years of age, 60 percent already have at least one heart disease risk factor, such as high cholesterol or high blood pressure.[33] Obese children also have an increased risk of Type II diabetes, aggravated existing asthma, sleep apnea, decreased physical functioning and other negative physical effects. [34], [26]
The growing obesity trend among adults is an alarming indication of what could happen to today’s children. The following maps of the United States provide a portrait of the growth of obesity among U.S. adults since 1985. The maps show the percentage of U.S. adults in each state with a body mass index (BMI) of 30 or more, meaning they meet the medical definition of obesity for adults.[23]
Obesity Trends Among U.S. Adults: 1985
(BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman)
Obesity Trends Among U.S. Adults: 1990
(BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman)
Obesity Trends Among U.S. Adults: 1995
(BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman)
Obesity Trends Among U.S. Adults: 2000
(BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman)
Obesity Trends Among U.S. Adults: 2004
(BMI ≥ 30, or ~ 30 lbs overweight for 5’ 4” woman)
Images: Centers for Disease Control and Prevention, Overweight and Obesity Trends.[35]
Developmental Health
While the physical health effects of obesity and lack of physical activity are becoming better understood, less is known about the impacts of the decline in walking and bicycling on child development. Adults, whose chief concerns pertain to children’s health and safety, often forget that walking and bicycling to school may be a child’s first chance at independence.
Some children today have less independence than their parents did, and this lack of independence can negatively impact their social behavior development.[36] Driving a child from home to school limits the child’s opportunities to interact with their neighborhood and other children. Questions also have been raised regarding how children who spend all their travel time in motor vehicles will master fundamental pedestrian and bicycling skills and what kind of drivers they will become because of their lack of experience negotiating traffic as walkers or bicyclists. Children who spend more time in supervised structured activities have fewer opportunities to explore their neighborhoods. Children may lose some relatively safe opportunities to make decisions independently. They miss some of the lessons gained from learning from mistakes and the confidence that comes with success.[37]
Environmental Health
Less walking and bicycling and more motor vehicle traffic can negatively impact air quality. In many cities across the United States the motor vehicle is the single greatest polluter.[38] Each year, motor vehicles emit millions of tons of pollutants into the air. Pollution control measures initiated in the past two decades have helped to reduce emissions per vehicle, yet auto emissions have continued to rise because people have doubled the miles they drive in that same time period.[39] Estimates from multiple cities indicate that the motor vehicle traffic generated by the travel to and from school adds 20 percent to 30 percent more traffic volume to the roads.[40], [41]
Atlanta, Georgia.
Approximately 5 million children in the United States suffer from asthma, causing over 14 million lost school days per year.[42] Children and adults with asthma are particularly sensitive to poor air quality. The 1996 Olympics in Atlanta provided an opportunity to examine the relationship of traffic, air quality and health. During the 1996 Summer Games, Atlanta virtually banned single-occupant motor vehicles downtown in order to prevent gridlock. A study of the ban and its effects shows a clear relationship between traffic reduction and fewer incidents of asthma attacks that required medical attention. Researchers found that morning rush-hour traffic volumes decreased by more than 23 percent and peak ozone amounts decreased by 28 percent during the 17 days of the Olympics.[43] Also, there was a 42 percent decrease in asthma related hospitalizations, emergency department visits and urgent care visits for children during the Olympics compared to the four weeks before and after the games.[43]
Natomas Elementary School, Sacramento, California.
Safe Routes to School programs help to reduce auto emissions by encouraging non-motorized forms of transportation, such as walking and bicycling to school.[44] A recent report by the U.S. Environmental Protection Agency used data from schools in Florida to compare travel choices and air quality implications. School location and the quality of the built environment between home and school affect how children get to school. The study concluded that schools located closer to students’ homes in walkable neighborhoods would reduce traffic, produce a 13 percent increase in walking and biking and a reduction of at least 15 percent in motor vehicle emissions.[44]