Obesity is a condition in which the body has excess fat. Childhood obesity has become an important public health issue because affects every aspect of the life of a child. More specifically, the condition leads to poor health and negative social perceptions. Many risk factors are linked to obesity. The varying aspects of the problem and its serious implications for future health and well-being of children are enormous. The most effective solution can be achieved via programs geared to prevent such diseases. Children spend an average of more than three hours daily in front of the television, an hour at the computer, and 30 minutes playing video games, which opens major opportunities for us to propose a mobile game approach to prevent childhood obesity (MACO) using persuasive technology. MACO is a game-based persuasive mobile technology designed to inspire children to apply healthy eating habits as well as to begin and continue being physically active. This technology also introduces fun activities to motivate children to exercise more and encourage them to choose healthier food in appropriate amounts. A study on persuasive technologies application and childhood obesity prevention is conducted to determine the best persuasive technology application for MACO. The study proposes a framework and develops a system prototype. © 2014 IEEE.