> We don’t predict portion sizes yet. At the moment we give a sane default and ask the users to adjust it.

This is a serious problem. Research suggests that one of the main causes of obesity in children is lack of ability to identify portion sizes or understand how much to eat.

Obviously there is a market of people who understand this well and want to track what they eat, but you are very likely going to be misleading a very significant amount of your userbase into making worse decisions for themselves.