DS does not know the word "fat". We don't use it. For that exact reason! However, DS is interested in other differences such as height, age, skin colour and nose shape. All innocent and all things I can talk about. I'm also teaching him which words to use to women - you don't call a girl "big". His best friend recently compared sizes with "I'm small and you're big. Mummy, you are big, but not as big as a house" so we don't use big for girls any more. We use "tall" and "small" to describe height.

As for colours, he will look at very, very black people, but mostly he will say someone has a different colour face (if he bothers to comment) and that's fine. They do. He will refer to "that boy" or "that girl"... if he sees people with different skin colours as being human just like him, that's not really racism. Just an observation.

Might be robbing him of innocent words, but hearing a male colleague tell a female colleague she has skinny legs (and being re-educated about the word "slender")... I'd rather start him off early. The same colleague also offered to mathematically prove that I had the same gravitational attraction as the earth. Massive attractive power I can cope with, same size as a planet I do not.