I'm using Windows 8, Internet Explorer 11, and not getting any response when I try to add a just-created custom food to my food log. Tried twice, and so I'm pretty sure I'm not saving that custom food either.
I can go to Chrome (which I will do) but I wanted to report the problem. It's one of those 'dead in the water' situations where you can't do anything with the custom food. I can enter this post, though, as you can see.