Objectives: To examine appetite traits, level of physical activity, and television (TV) time as predictors of change in Body Mass Index Standard Deviation Score (BMI SDS) from age 6 to 8 and to explore the effect of BMI SDS (from age 4) on appetite traits. Methods: In all, 995 Norwegian children participated at age 4; 760 and 687 of these children took part in the assessment at ages 6 and 8, respectively. Appetite traits were assessed using the Children’s Eating Behavior Questionnaire, activity was measured using accelerometers, and TV time was based on parental reports. Results: High food responsiveness predicted a steeper increase in BMI SDS. A reversed effect was also observed: High BMI SDS predicted increased food responsiveness and decreased satiety responsiveness. Physical activity and TV time were unrelated to BMI SDS. Conclusion: Children whose eating is especially triggered by the sight and smell of food show prospective increased weight gain. Excess weight and weight gain also predict increased food-approaching behavior.