The main purpose of the Personal Health Investment Today Act of 2025, known as the PHIT Act, is to encourage healthier lifestyles and prevent diseases related to obesity. It aims to provide financial incentives for individuals and families to engage in physical activities and fitness, thereby reducing the financial burden associated with maintaining a healthy lifestyle. Key provisions of the PHIT Act include changes to the Internal Revenue Code that allow certain expenses related to physical activity, fitness, and exercise to be treated as medical care.