ACT and diabetes

I have ordered the book co-authored by Steve Hayes on this topic, and greatly look forward to its arrival. Until then I need to prepare for a couple of sessions with a client who has dangerously high blood sugar levels and who overeats. I didn't want to re-invent the wheel...does anyone have any ideas on how to approach over-eating/diabetes/reluctance to exercise, using ACT? Thank you! Catharina