The Jagged Little Pill star battled both bulimia and anorexia when she was a teenager and admits her struggles with food were linked to her desire to bury her feelings.
Writing in her blog for iVillage.com, the 37-year-old songstress, who has an 11-month-old son with her rapper husband Mario “Souleye” Treadway, said: 'There are often traumas and abuses/neglect that are begging to be healed.
“Fat can be a way to protect ourselves and survive, a way to control something in a world where everything feels out of control, and a way to stave off profound fear of feeling our feelings.
“I often find anxiety, fear, boredom, disappointment, loneliness, excitement and grief to be the top feelings food can attempt to prevent.'
Despite successfully overcoming her eating disorders, Morissette says she still has a “fraught” relationship with food.
She said: 'My fraught relationship with food and fat has always been a cloaked invitation into a more profound kindness to myself (one I have so often ignored).
“Being kind toward my fragility in the face of a monolithic message of perfectionism and intolerance has not been an easy path – nor, I'm ashamed to say, a consistent one. Writing about it helps.'