One thing I'm reminded of...
It's NEVER the diet but it ALWAYS is!
Everytime someone gets too fat they always say that diet is not a problem. They assume that they are training the wrong way.
Why? Because changing training program is fun.
Eating less and cutting out some of the food you like isn't.
We would all prefer if the problem was always the training, easy to fix, not hard to stick to. But in some cases it's just not the training.