If you select a tag in browse you will see at bottom left some public collections. Chances are, that people put similar games on a collection.
So find any of the games you like and look what tags are commonly used. The suggested tag box is not exhaustive. On the other hand, just because a tag exists on other sites, does not mean, that people will use it here. So go on game pages of games and click the links in the more information box.
Things like body shape are seldom tagged. Activities more often. So there is a eating and stuffing tag used. There is no slim tag, but some people use fat as a tag.