Normative influence on dietary decision making was assessed as a function of the referent informational influence model within an extended theory of planned behavior framework. In a longitudinal design, university students (N = 141) completed measures of attitudes, perceived behavioral control, subjective norms, referent group norms, and intentions toward healthy eating, with healthy eating behavior reported 2 weeks later (n = 82). A distinction was made between injunctive and descriptive norms, in line with norm focus theory. The extended theory of planned behavior and referent informational influence models were partially supported. An interaction between group injunctive and descriptive norms emerged such that misaligned group norms were associated with healthier eating behavior than aligned group norms (both supportive and unsupportive). Theoretical and applied implications are discussed.