I don't know why your doc would be upset if you are getting enough nutrients. The meal replacement shakes and bars are pretty nutrient dense in good proportions. My biggest issue with them is that it isn't sustainable - I can't replace many meals long term with them. They just aren't satisfying. If I lean too heavily on them as a way to keep calories low, I will likely fail. I do use them (usually bars) if I am rushing out the door and won't really have time to stop for a meal or if I didn't bring a lunch and don't have time to go out. Filling in for a meal that I would have skipped if I didn't have a quick choice is a fine use for them IMO.