A Randomized Controlled Trial of Students for Nutrition and eXercise (SNaX)

Objectives: We conducted a randomized controlled trial (RCT) of Students for Nutrition and eXercise (SNaX), a middle-school-based obesity-prevention intervention combining school-wide environmental changes, multimedia, encouragement to eat healthy school cafeteria foods, and peer-led education and marketing. Methods: We randomly selected schools from the Los Angeles Unified School District (LAUSD) and assigned five to the intervention group and five to a wait-list control group. School records were obtained for number of fruits and vegetables served, students served lunch, and snacks sold per attending student. Pre- and post-intervention surveys assessed psychosocial variables among 2,997 seventh-graders (75% of all seventh-graders across schools). Hypotheses: For the RCT of SNaX, we hypothesized that SNaX would lead to increases in the proportion of students served in the cafeteria (because SNaX markets cafeterias' healthy foods); increased fruit and vegetable servings (because SNaX increases access to sliced/bite-sized fruits and vegetables); decreased school store snack sales; and greater water consumption. We also hypothesized that SNaX would lead to more positive attitudes about the cafeteria and water, improve obesity-prevention knowledge, and increase intentions to drink water.

These schools received the entirety of Students for Nutrition and eXercise, a middle-school-based obesity-prevention intervention combining school-wide environmental changes, multimedia, encouragement to eat healthy school cafeteria foods, and peer-led education and marketing

These schools received the entirety of Students for Nutrition and eXercise, a middle-school-based obesity-prevention intervention combining school-wide environmental changes, multimedia, encouragement to eat healthy school cafeteria foods, and peer-led education and marketing

We obtained the number of students obtaining lunch per day (by National School Lunch Program (NSLP) eligibility) from schools.

Attitudes about the cafeteria were calculated by survey data using the mean of two 7-point scales representing attitudes about the cafeteria: unsatisfying/satisfying and bad for my health/good for my health.

Attitudes about water were measured with a survey including an 11-point scale (very negatively/very positively).

Knowledge about healthy eating and physical activity was measured with a survey containing 6 true/false items.

Intentions to drink water were assessed with two survey items, "How likely is it that you will drink water [or drink water from a refillable water bottle] the next day you are in school?" with 5-point scales (extremely likely/extremely unlikely).

Water consumption frequency was assessed by survey with, "How often do you usually drink tap water?" and "How often do you usually use a refillable water bottle to drink water?" (every day, a few times a week, once a week, twice a month, once a month, less than once a month, never).

Inclusion Criteria: schools with >50% NSLP-eligible students (a proxy for low-income) and <900 - seventh-graders Exclusion Criteria: schools with <50% NSLP-eligible students and >900 seventh-graders

Bogart LM, Cowgill BO, Elliott MN, Klein DJ, Hawes-Dawson J, Uyeda K, Elijah J, Binkle DG, Schuster MA. A randomized controlled trial of students for nutrition and eXercise: a community-based participatory research study. J Adolesc Health. 2014 Sep;55(3):415-22. doi: 10.1016/j.jadohealth.2014.03.003. Epub 2014 Apr 29.