A pretest-posttest field test with control group (N = 189 parent-child dyads) tested a structural model representing youths' (ages 9-14) perspectives to examine the efficacy of a family-centered, media literacy-oriented intervention promoting fruit and vegetable consumption. The intervention facilitated critical discussion about nutrition and media, mentored by the parent. Results showed that youths' increases in fruit and vegetable consumption flowed from parent-child discussion of nutrition labels, which was predicted by child-initiated discussion, critical thinking about media sources, and critical thinking about media content. Multivariate analyses revealed that the intervention was productive for all participating age groups and for all dependent variables. The results suggest that a developmental progression from critical thinking about source to critical thinking about content affects behavior change and can be catalyzed through media literacy education and encouragement to discuss media messages (i.e. practice) with parents.