I have difficulty verbalising emotions and ideas. When writing I have time to think away from people who, I find, inhibit thought. My internal censor is less vigilant. Reading work in public helps me express emotion and use appropriate non-verbals rather than smiles. Communication barriers were broken when I showed certain poems to my family.
Writing is a form of release, perhaps partly physical.
Emotions are externalised. I can distance myself from, and gain a new perspective on, them. Compulsive eating can be frightening, you feel out of control, almost possessed. Writing is a form of control. It enables me to explore the compulsion more fully, to identify issues and their underlying logic.