Background In Ho Chi Minh City, Vietnam, recent studies found a rapid increase in overweight and obesity in adolescents. There is a need for effective health promotion interventions to support healthy diets and encourage a physically active lifestyle. This study will help fill an evidence gap on effective interventions to prevent excess weight gain in adolescents and generate new insights about peer-led education to promote healthy lifestyles. Objective We aim to assess the feasibility and acceptability of a combined peer-led and peer support intervention among junior high school students in Ho Chi Minh City. Additionally, the efficacy of the intervention on adolescents’ dietary practices and time spent on physical activity will also be measured in this pilot study. Methods The Peer Education and Peer Support (PEPS) project is a pilot cluster randomized controlled trial with 2 intervention and 2 control schools. The intervention consists of 4 weekly education sessions of why and how to choose healthy food and drinks and how to be more physically active. Additionally, the intervention includes a school-based and online support system to help maintain student engagement during the intervention. We will use in-depth interviews with students, peer leaders, teachers, and parents; focus group discussions with peer educators; and direct observation of the school environment and peer leaders’ interactions with the students. Acceptability and feasibility of the intervention will be assessed. We will also quantitatively assess limited efficacy by measuring changes in student’ physical activity levels and dietary behaviors. Results We delivered the peer education intervention at the start of each school year over 3 months for all new grade 6 adolescents in the selected schools, followed by peer support and home engagement activities over 6 months until the end of the school year. There was a baseline assessment and 2 post-intervention assessments: the first immediately after the intervention to assess the short-term impact and the second at the end of the school year to assess the sustained impact on changes in adiposity, diet, and physical activity. Conclusions The findings of this study will be used to develop a larger-scale cluster randomized controlled trial to examine the impact of a multicomponent, school- and home-based health promotion intervention. The trial will use innovative peer education methods to reduce overweight and obesity and improve dietary choices and physical activity levels in Vietnamese adolescents. Trial Registration Australian New Zealand Clinical Trials Registry ACTRN12619000421134; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=376690&isReview=true International Registered Report Identifier (IRRID) DERR1-10.2196/15930

Background: Adolescence is a period of life when dietary patterns and nutrient intakes may greatly influence adult fatness. This study assesses the tracking of energy and nutrient intakes of Ho Chi Minh City adolescents over five years. It explores the possible relationships between energy and the percentage of energy from macronutrients with BMI. Methods: Height, weight, time spent on physical activity, screen time and dietary intakes were collected annually between 2004-2009 among 752 junior high school students with a mean age was 11.87 at baseline. The tracking was investigated using correlation coefficients and weighted Kappa statistics (k) for repeated measurements. Mixed effect models were used to investigate the association between energy intakes and percentage energy from macronutrients with BMI. Results: There were increases in the mean BMI annually, but greater in boys than in girls. Correlation coefficients (0.2 < r < 0.4) between participants’ intakes at baseline and 5 year follow-up suggest good tracking. Extended Kappa values were lowest for energy from carbohydrate in both girls and boys (k = 0.18 & 0.24, respectively), and highest for protein in girls (k = 0.47) and fat in boys (k = 0.48). The multilevel models showed the following variables significantly correlated with BMI: Carbohydrate, fat, percentage of energy from carbohydrates, fat, time spent for MVPA, screen time, age and gender. Conclusions: The poor to fair tracking observed in this cohort suggests that individual dietary patterns exhibited in the first year are unlikely to predict energy and nutrient intakes in the fifth year.