Health problems, even minor ones, can interfere with or even overshadow other aspects of your life. Even relatively minor health issues such as aches, pains, lethargy, and indigestion take a toll on your happiness and stress levels.
Being physically healthy enables you to have better overall health, including in your relationships. You only get one body, so taking care of it is important.
Making a commitment to healthier habits is the only way to improve your ability to cope with stress, and take care of body.