Using multi-theory model to predict initiation and sustenance of small portion size consumption among college students

Background: Consumption of large portion sizes is contributing to overweight and obesity. College students are a vulnerable group in this regard. The purpose of this study was to use multi-theory model (MTM) to predict initiation and sustenance of small portion size consumption in college students. Methods: A total of 135 students at a large Southern US University completed a 35-item valid (face, content, and construct) and reliable (internally consistent) survey electronically in a cross-sectional design. The main outcome measures were intention to start eating small portion sizes and continuing to eat small portion sizes. Only those students who ate large portion sizes during the past 24 hours were included. Results: Stepwise multiple regression showed that initiation of small portion size consumption was explained by participatory dialogue (advantages outweighing disadvantages), behavioral confidence, age, and gender (adjusted R-2 = 0.37, P < 0.001). Males were less likely to initiate small portion size consumption than females (beta = -0.185, 95% CI = -0.71-0.11). Regarding sustenance, emotional transformation, changes in social environment, and race were the significant predictors (adjusted R-2 = 0.20, P < 0.001). Whites were less likely to sustain small portion size change than other races (beta = -0.269, 95% CI = -0.97 - -0.26). Conclusion: Based on this study's findings, MTM appears to be a robust theoretical framework for predicting small portion size consumption behavior change. Interventions in this regard need to be designed.