Predicting Milk and Soft Drink Consumption Among Female Adolescents Using the Theory of Planned Behavior

A total of 756 female adolescents, aged 13 to 18 years, from five public high schools in Antelope Valley Union High School District located in North Los Angeles County participated in this study between February 1999 and March 1999. The ethnic composition was 53.3% White/Anglo Americans, 19.3% Hispanics or Latinos and 10.2% Black/African Americans. The constructs of the Theory of Planned Behavior (attitude, subjective norm, and perceived behavioral control and their underlying beliefs) were assessed to determine the predictors of low-fat milk and regular soda consumption. A cross-sectional design with group-administered questionnaires was utilized. Most participants (89.6%, n = 636) reported that they currently drink milk; 64.3% (n = 456) of all participants reported drinking reduced-fat milk and nonfat milk. Most participants 96.3% (n = 681) reported that they currently drink soda; 84.3% (n = 596) reported drinking regular soda. Attitude, subjective norm, and perceived behavioral control explained 66% of the variation in the intention to drink low-fat milk and 64% of the intention to drink regular soda. The strongest predictor for both drinks was attitude, followed by perceived behavioral control and subjective norm. The primary expected outcomes that predicted a positive attitude towards drinking low-fat milk were enjoyment of taste and feeling healthy. Weaker predictors were having more energy and not expecting stomachache or gas upon its consumption. Normative beliefs of students about what parents thought about milk use predicted subjective norm. Perceived behavioral control was predicted by availability of low-fat milk at home. The primary expected outcomes that predicted a positive attitude towards drinking regular soda were enjoyment of taste, quenching of thirst, becoming hyper or having a sugar rush, and feeling healthy. Students had a negative attitude towards drinking regular soda if they felt that drinking it might cause them to gain weight. Normative b