is there a food builder on this site ?

yep, tha'ts what I do. I have everything I make often in my recipe file. You can also click quick tools under each meal, and click remember meal, give it a name, and when you eat the same thing again, you click "add food" then the meals tab, or the recipe tab, wherever you filed it. That's what my green smoothie is, and when I change ingredients, I simply goi into the recipe and change one of the ingredietns.