It occurred to me that she didn't have do this. She had a choice to not do the diet. Even better, she had the choice to do the diet at her own pace. I advised her to not mind the dietitian too much, but if she really wanted to do the diet, she should stay committed to it, and do it at a pace she felt comfortable. So no, no habits and routines need to be changed overnight. She could do it over a period of weeks or months. So long as she's gaining weight, it should be OK to take the time!
The next morning I got a call from her, that this simple hack made her feel like a burden has been lifted.
Photo credit to Huang Did, Flickr.