BACKGROUND: Stages of change are related to dietary fat consumption. Few studies have examined stage occupation within the context of purchasing low-fat foods. OBJECTIVE: To determine the stage-prevalence of individuals for purchasing low-fat foods; identify the frequency of misclassification into action and maintenance (A/M) stages for purchasing for low-fat foods; and explain the demographic and cognitive-variable differences between pseudo (or false positive) A/M and true A/M individuals. DESIGN: Data were collected using a self-administered questionnaire among English-speaking adults (n=1,001) who were randomly sampled by mail. STATISTICAL ANALYSES PERFORMED: Descriptive statistics were used to compare the characteristics of the stage groups. Groups were compared using chi(2) tests and Student t test. RESULTS: Of those who reported being in A/M stages, 32% were misclassified by the staging algorithm and were not true A/M low-fat food purchasers. CONCLUSIONS: Individuals who are in A/M stages for buying low-fat foods still purchase high-fat foods. Stage misclassification may be a persistent problem in studies of dietary change using the Transtheoretical Model.
BACKGROUND: Stages of change are related to dietary fat consumption. Few studies have examined stage occupation within the context of purchasing low-fat foods. OBJECTIVE: To determine the stage-prevalence of individuals for purchasing low-fat foods; identify the frequency of misclassification into action and maintenance (A/M) stages for purchasing for low-fat foods; and explain the demographic and cognitive-variable differences between pseudo (or false positive) A/M and true A/M individuals. DESIGN: Data were collected using a self-administered questionnaire among English-speaking adults (n=1,001) who were randomly sampled by mail. STATISTICAL ANALYSES PERFORMED: Descriptive statistics were used to compare the characteristics of the stage groups. Groups were compared using chi(2) tests and Student t test. RESULTS: Of those who reported being in A/M stages, 32% were misclassified by the staging algorithm and were not true A/M low-fat food purchasers. CONCLUSIONS: Individuals who are in A/M stages for buying low-fat foods still purchase high-fat foods. Stage misclassification may be a persistent problem in studies of dietary change using the Transtheoretical Model.