A school-based intervention improved dietary intake outcomes and reduced waist circumference in adolescents: a cluster randomized controlled trial

Abstract

BackgroundIn Ecuador, adolescents’ food intake does not comply with guidelines for a healthy diet. Together with abdominal obesity adolescent’s inadequate diets are risk factors for non-communicable diseases. We report the effectiveness of a school-based intervention on the dietary intake and waist circumference among Ecuadorian adolescents.MethodsA pair-matched cluster randomized controlled trial including 1430 adolescents (12–14 years old) was conducted. The program aimed at improving the nutritional value of dietary intake, physical activity (primary outcomes), body mass index, waist circumference and blood pressure (secondary outcomes). This paper reports: (i) the effect on fruit and vegetable intake, added sugar intake, unhealthy snacking (consumption of unhealthy food items that are not in line with the dietary guidelines eaten during snack time; i.e. table sugar, sweets, salty snacks, fast food, soft drinks and packaged food), breakfast intake and waist circumference; and, (ii) dose and reach of the intervention. Dietary outcomes were estimated by means of two 24-h recall at baseline, after the first 17-months (stage one) and after the last 11-months (stage two) of implementation. Dose and reach were evaluated using field notes and attendance forms. Educational toolkits and healthy eating workshops with parents and food kiosks staff in the schools were implemented in two different stages. The overall effect was assessed using linear mixed models and regression spline mixed effect models were applied to evaluate the effect after each stage.ResultsData from 1046 adolescents in 20 schools were analyzed. Participants from the intervention group consumed lower quantities of unhealthy snacks (−23.32 g; 95% CI: −45.25,-1.37) and less added sugar (−5.66 g; 95% CI: −9.63,-1.65) at the end of the trial. Daily fruit and vegetable intake decreased in both the intervention and control groups compared to baseline, albeit this decrease was 23.88 g (95% CI: 7.36, 40.40) lower in the intervention group. Waist circumference (−0.84 cm; 95% CI: −1.68, 0.28) was lower in the intervention group at the end of the program; the effect was mainly observed at stage one. Dose and reach were also higher at stage one.ConclusionsThe trial had positive effects on risk factors for non-communicable diseases, i.e. decreased consumption of unhealthy snacks. The program strategies must be implemented at the national level through collaboration between the academia and policy makers to assure impact at larger scale.Trial registration ClinicalTrial.gov-NCT01004367.

Risk Factors and Prevalence of Abdominal Obesity among Upper-Secondary Students

“…According to research carried out in a group of girls from rural areas, irregular breakfasts and skipping meals throughout the day were significantly related to the prevalence of abdominal obesity [39]. Despite the fact that our study did not show a correlation between the consumption of selected products and the parameters of abdominal obesity, other researchers emphasised such a relationship [49].…”

Students’ Conceptions of Sustainable Nutrition

“…Other factors, such as the socioeconomic status of parents, have a major influence on the nutritional behavior of young people [90]. However, in samples with nearly the same socioeconomic status, nutritional interventions in schools showed an effect on the nutritional behavior of students [91].…”

Healthy lifestyles and noncommunicable diseases: Nutrition, the life‐course, and health promotion

“…It is imperative to intervene as early as possible, at the individual level, to combat obesity, which predisposes to noncommunicable diseases, to avert reaching a point where dietary interventions are inefficient 113 . Health promotion targeting individuals is effective 115–118 . Apart from healthy nutrition, exercise can also help to combat overweight/obesity 119–121 …”