Transtheoretical model-based nutritional interventions in adolescents: a systematic review

Abstract

Background Literature has shown a tendency of inadequate eating habits among youth, consequently, nutritional interventions are required. The Transtheoretical Model (TTM) classifies individuals based on their readiness to change. This model is widely used for health education interventions and it has been associated with positive results. Purpose This review aimed to describe how the TTM has been applied to nutritional interventions for adolescents. Methods The Adolec, Google Scholar, LILACS, PsycINFO, PubMed, Science Direct and Web of Science databases were searched. Only full original articles written in English, Spanish or Portuguese on randomized controlled trials and quasi-experimental designs that applied the TTM to nutritional interventions targeting adolescents were included, with no restrictions on publication date. Results The initial search yielded 3779 results, of which 13 were included. Two more articles were added after a search update, totaling 15 articles. The included adolescents were mostly recruited from schools, and the duration of the studies ranged from one month to three years. The TTM was used alone or combined with other behavior-change theories. Nine interventions had positive results. The participants in six studies progressed through stages of change or improved decisional balance. Conclusion There are some limitations related to the studies included in this review, such as the differences in design and intervention exposure time, as well as using the TTM in association with other behavior-change theories. Nevertheless, the TTM seems to be a successful strategy for nutritional intervention in adolescents. Further studies comparing the TTM with other behavior-change theories should be conducted to better understand its effectiveness.