Texts For Healthy Teens: A Health Education Program for Adolescents

The overall objective is to examine if participating in an SMS-transmitted health educational program targeting a cluster of dietary factors over a period of weeks during the years of adolescence can induce durable changes towards more healthful dietary habits and body weight trajectories. The investigators will examine if impact is reinforced by asking a friend of the participant to also participate; if impact is reinforced by asking the mother of the participant to also participate; and if impact is reinforced when the SMS-transmitted health promotion program is designed to target a specific dietary factor only - decided upon from participants\' reporting of their dietary habits at the beginning of the program - rather than to simultaneously target a cluster of dietary issues uniform for all participants.