The prevalence of obesity has dramatically increased over the past decades. Obesity is generally accompanied by physical inactivity, and has become a global pandemic and recognized as a primary public health concern in many countries. Obesity affects kinematics and kinetics, which likely causes changes of foot structure and function. For obese individuals, weight reduction and increasing weight bearing physical activity may be effective approaches to not only decrease the risk of the health-related diseases and improve the QoL, but also have positive impact on foot structure and function. However, there has been no systematic study on the influence of weight reduction and increasing weight bearing physical activity on foot structure and function in obese adults to date.