Is there a link between weight gain and flat feet?

Gaining weight increases the strain on delicate structures in your feet, such as the plantar fascia, ligaments, tendons, and the bones in the foot and ankle. All of these bear the vast majority of your body weight, and their structure can change over time due to excessive strain. There is a lot of research showing a link between increased body weight and flat feet. As you get back on your feet following your injury, becoming more active and losing weight, you should find that any feelings of pain, strain and fatigue in your feet gradually improve.