Any mature, somewhat evolved adult understands that it cannot possibly be someone else’s fault (trainer or otherwise) for not achieving personal goals. I’m sure there is something in any Psych 101 textbook that could explain such behavior….
I guess the issue becomes one of “can I still work with this person?”; “is he/she respecting me and my efforts?; “is he/she honestly putting forth the energy and effort required to achieve their goals?”.
Have you introduced the following into the conversation?:
-why are you coming to see me only once a week? What do you do the other 6 days to contribute to this goal?
-a food diary (a good quantitative source, if he/she completes it honestly!)
-an understanding of what realistic, healthy weight loss looks like i.e., 1-2 pounds a week
-the energy output necessary to burn the necessary “excess” calories
-the necessary frequency and intensity of “productive” physical activity sessions
-WHY does he/she want to lose weight i.e, is it personally driven or a real or felt external pressure?
Thing is, weight is such a delicate topic. So, as you’ve probably discovered, so many layers have to be lifted before you may make any real progress. Still, if this person has come to you, he/she must have some degree of motivation…