Furthermore, parents can be effective advocates in their schools and communities for increased recess, physical education, recreational facilities, playgrounds, parks, and sidewalks.

It is also important for parents, children, and youth to take advantage of the opportunities for physical activity that come along throughout the day and to realize that not all physical activity has to be a planned event. Examples include walking to do errands or having children walk at the grocery store or mall rather than ride in shopping carts or strollers.

DECREASING INACTIVITY

A complementary strategy for promoting physical activity among children and youth is to decrease their inactivity. Of the sedentary behaviors that may be linked to the upsurge in childhood obesity, television watching has been most widely studied. Other types of screen time (such as computer use and video game playing) have not been researched as extensively with regard to obesity, though they share many similarities in principle; various combinations, in fact, are often examined along with television in studies of media use and obesity. One study found that the time spent watching television, taped television shows, or commercial videos averaged per day: 2.5 hours for children between the ages of 2 and 7, 4.5 hours for 8- to 13-year-olds, and 3.3 hours for 14- to 18-year-olds (Roberts et al., 1999). The 2003 Youth Risk Behavior Surveillance nationwide survey found that 38.2 percent of high school students reported watching television three hours or longer on an average school day; 67.2 percent of African-American students, 45.9 percent of Hispanic students, and 29.3 percent of white students reported three or more hours of television viewing (CDC, 2004c).

Television viewing may have a negative effect on both sides of the energy balance equation. It may displace active play and physical activity time, and it is associated with increased food and calorie intake—as an accompaniment of television viewing, as a result of food advertising, or both (Robinson, 2001a). Many epidemiological studies have found positive associations between increased prevalence of obesity or overweight and greater lengths of television viewing time, although comparing the results is difficult due to differences in methods and reporting (reviewed by Robinson, 2001b). Gortmaker and colleagues (1996) found a strong positive association between parent or child reports of children’s television watching time and prevalence of obesity. This study of 746 children and youths (ages 10 to 15 years) found that those who watched more than five hours of television per day were 4.6 times as likely to be obese as those watching zero to two hours. This observation held when adjusted for maternal overweight, SES, and other factors.

Similarly, Crespo and colleagues (2001) found that in a sample of



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