It seems like our consciousness is constructed in such a way that it's very easy for people to forget that we actually have a body connected to our head.
Another interesting idea would be to think that mental health problems in part are caused by the systems inside our body that are outside of our conscious control not working properly communicating their discomfort as mental health problems.
I'm a clinical psychologist and I don't think I've had a patient in therapy who had
1. Sleep 2. Exercise 3. Stress 4. Food
Figured out.
What I mostly notice is that once these things are improved the need for therapy diminish significantly.