I've seen this program around, but never looked very closely at it. It looks really interesting and effective if done right. I was curious if people use their own containers by knowing the sizes. So the answer is yes, they certainly can. LOL
When I was vegan, I measured my food by cups, so I'm drawn to the container idea for preparation and portion sizes.
I miss being vegan and definitely see it in my future again. I never forced it on my kids, though, but Gabe was vegan, too.
I used advice from Esselstyn, McDougall and Fuhrman. Pretty much similar to this guide: http://www.veghealthguide.com/. You can see how it would all work well for me in the containers. There were many times that I had a hard time eating all of the food I needed in a day. Containers would remind me what I have left. Sort of how I can get with drinking enough water. When I measure it out or check it off, it makes it easier.