The World Health Organization (WHO) has declared obesity as a 21st-century epidemic after reaching global proportions. In Spain, this disease is suffered by 62% of the population, leading to the emergence of new health problems. Increasing childhood obesity in the world is a direct result of changes in the lifestyles of the population. Therefore, in this paper we present a gamification training program to prevent childhood obesity based on motor games, and active videogames developed for overweight children ages 8–12. The design of the program consisted of: group sessions in a school setting, individual sessions at home for the children, and developing healthy habits to help families. The motivation and the effectiveness of the gamification training program were studied. The results involving biometric variables, learning healthy habits and experience in the intervention were highly satisfactory. •We design a training program based on a GBL and gamification approaches.•We work in formal and informal contexts (school and home) as informal learning.•We present a cuasi-experimental study developed with children from 8 to 12 years old.•We analyze the experience from different dimensions (medical, learning and UX).