If people maintain the belief systems that empower them, they'll keep coming back with enough action and enough resourcefulness to succeed eventually.
You must find a more empowering source of comfort, connection, and control than food. Perhaps a creative outlet, helping others, becoming active in an organization, whatever.
The "I've tried everything" story ensures failure. You must create an empowering story that recognizes that everyone has failed a lot but successful people have found a way to rebound until they succeed.