A Randomized Controlled Trial of Students for Nutrition and eXercise: A Community-Based Participatory Research Study

Abstract

Purpose To conduct a randomized controlled trial of Students for Nutrition and eXercise (SNaX), a 5-week middle-school-based obesity-prevention intervention combining school-wide environmental changes, multimedia, encouragement to eat healthy school cafeteria foods, and peer-led education. Methods We randomly selected schools (five intervention, five wait-list control) from the Los Angeles Unified School District. School records were obtained for number of fruits and vegetables served, students served lunch, and snacks sold per attending student, representing an average of 1,515 students (SD=323) per intervention school and 1,524 students (SD=266) per control school. A total of 2,997 seventh-graders (75% of seventh-graders across schools) completed pre-and post-intervention surveys assessing psychosocial variables. Consistent with community-based participatory research principles, the school district was an equal partner and a community advisory board provided critical input. Results Relative to control schools, intervention schools showed significant increases in the proportion of students served fruit and lunch and a significant decrease in proportion of students buying snacks at school. Specifically, the intervention was associated with relative increases of 15.3% more fruit served (p=0.006), 10.4% more lunches served (p<0.001), and 11.9% fewer snacks sold (p<0.001) than would have been expected in its absence. Pre-to-post intervention, intervention school students reported more positive attitudes about cafeteria food (p=0.02) and tap water (p=0.03), greater obesity-prevention knowledge (p=0.006), increased intentions to drink water from the tap (p=0.04) or a refillable bottle (p=0.02), and greater tap water consumption (p=0.04) compared to control school students. Conclusions Multi-level school-based interventions may promote healthy adolescent dietary behaviors.

Two-Year BMI Outcomes From a School-Based Intervention for Nutrition and Exercise: A Randomized Trial

“…Further descriptions of SNaX (including the setting, design, and results) are available in earlier publications, 5,6,[15][16][17][18][19][20] and intervention materials are available at www. snaxinschools.…”

“…It also found greater obesity prevention knowledge, more positive attitudes about cafeteria food and tap water, increased intentions to drink water, and greater water consumption. 5, 6 SNaX combined school-wide environmental changes, encouragement to eat healthy food and engage in physical activity in school and at home, and peer-led education about healthy eating and physical activity. Interventions such as SNaX, which combine strategies to increase healthy nutritional intake and physical activity, have been more successful than those interventions that target only nutritional intake or physical activity.…”

“…Although SNaX lasted only 5 weeks, a primary goal of the program was to teach students skills that could be transferred to the family and to peers, as well as to instill healthier habits and provide students and parents with strategies for longer term behavior changes. 5 We hypothesized that SNaX would set in motion changes in behavior that ultimately would affect BMI. …”

The “Healthy Habits, Healthy Girls” randomized controlled trial for girls: study design, protocol, and baseline results

“…Overweight rates were higher in adolescents from disadvantaged backgrounds than those from non-disadvantaged communities. Most published school-based obesity intervention programs have been conducted in Australia 7,8 and the United States 24,25 .…”

The impact of dietary fibre intake on the physiology and health of the stomach and upper gastrointestinal tract

“…Even with meticulous consideration of other confounding lifestyle factors (Kratz, Baars, & Guyenet, 2013), such evidence cannot separate the impact of dietary fibre intake from the intake of its major dietary sources (i.e. fruits, vegetables and cereal products) from other putatively beneficial components within these foods (Mellen et al, 2007), or the broader effect that inclusion of high amounts of these foods within the diet may have to displace other less optimal food choices (Bogart et al, 2014;Lazzeri et al, 2013).…”