This is a 6-month randomized controlled trial. After the initial baseline screening and assessments, 60 overweight adolescents will be randomly assigned (30 subjects per group) to a standard weight-reducing diet with the advice to consume 8 cups of water per day (experimental group) or the same standard weight-reducing diet without additional advice (control group). The interventions will consist of nutrition education and behavioral counseling by a registered dietitian, during individual sessions and telephone calls. Mobile text messaging will be used to reinforce information presented at the individual sessions and thereby foster adherence to dietary advice. Diet prescriptions will differ only in regard to the specificity of recommendations regarding water consumption and physical activity recommendations will not differ between groups. The frequency and content of text messages will be consistent between the experimental and control groups, with the exception that the experimental group will receive an additional phrase with each message to encourage the "8 x8" water recommendation.