2012 Annual Report
1a.Objectives (from AD-416):
Objective 1: No longer applies
Objective 2: Develop and pilot test interventions to increase and sustain physical activity at a level consistent with the Dietary Guidelines for Americans (DG) in urban African- and Mexican-American children. Sub-objective 2A: Determine if adherence to the physical activity component of the DG is associated with a lower incidence of overweight/obesity in urban African- and Mexican-American children. Sub-objective 2B: Develop and pilot test an intervention with urban African- and Mexican-American children to increase physical activity consistent with the DG recommendation. Specifically, physical activity will be operationally defined as moderate to vigorous physical activity. Sub-objective 2C: Develop and pilot test a maintenance program with urban African- and Mexican-American children to sustain physical activity consistent with the DG recommendation. Specifically, physical activity will be operationally defined as moderate to vigorous physical activity.
1b.Approach (from AD-416):
A sample of 200 African- or Mexican-American middle school children (i.e., 6th – 8th grade; aged 10-15 years will be recruited from a Houston charter school to provide data on their participation in moderate to vigorous physical activity (MVPA). Measured body composition (i.e., height, weight, BMI, percent body fat) will be collected. This study will examine children's free-living participation in physical activity (PA) to determine if these behaviors are consistent with the Dietary Guidelines for Americans (DG) (i.e., 60 minutes of MVPA most days of the week). A questionnaire will be administered identifying PA barriers and facilitators to help determine activities most likely to encourage continued participation in PA. Subjects will be assessed to determine their level of adherence to PA that is consistent with the DG.
For objective 2. Level of physical activity was assessed using accelerometry for 200 participants. On average students engaged in moderate to vigorous physical activity for 44 minutes per day on weekdays (Monday through Friday) and 55 minutes on weekends (Saturday and Sunday). However, only 3% of children met the dietary guidelines recommendations for 60 minutes of physical activity during the weekdays and 5% of children met the dietary guidelines recommendations during the weekends. While few children are meeting the full recommendation of 60 minutes of physical activity per day, the average number of minutes of physical activity suggests that children are approximating the goal, particularly on weekends. It appears that increased efforts are needed to increase physical activity during the weekdays when children are in school. Assessment of body composition data revealed that while level of moderate to vigorous physical activity was not related to standardized body mass index, participation in hard to very hard physical activity decreased as standardized body mass index and percent body fat increased. A sample of 100 students have been recruited to participate in a physical activity intervention designed to increase moderate to vigorous physical activity in children in order to meet the daily physical activity recommendations. A questionnaire assessing barriers and facilitators to physical activity was administered. The most common barrier to physical activity reported was homework, followed by having a preference for watching television. As a result, the intervention was modified to increase physical activity during the school day and gradually decrease time spent watching television, playing videogames, and working on the computer. Students who received the intervention increased their participation in moderate to vigorous physical activity. These same 100 students were recruited to participate in a follow-up program designed to maintain increased levels of physical activity long term. We are in the process of collecting data regarding the maintenance of these increased levels of physical activity over time.
Increasing physical activity levels in minority children. Children are engaging in considerably less physical activity now than they were 20 years ago, and this decrease coincides with increased prevalence of obesity in youth. This is particularly important for minority children who are at greater risk for obesity-related health problems. Currently, the dietary guidelines recommend that children engage in 60 minutes of physical activity daily; however, there are multiple barriers that reduce the likelihood of children being active, such as the home environment, busy daily schedules, and preferences for sedentary behaviors. Children's Nutrition Research Center researchers in Houston, Texas, have developed an intervention program designed to increase physical activity in children in order to meet the dietary guidelines and have demonstrated that the program improved physical activity levels in minority children. This accomplishment has important implications for future policy development and may help address the obesity epidemic in minority children.