That's a pretty simple question, but it needs an answer.

Sometimes, I like getting a kind of chubby girl. Don't know why, I just like it from time to time.

However, I always have trouble to deal with their insecurities. They won't believe me if I tell them they're hot, or they will say "No, I'm fat " - to which I want to reply "well yeah, that's the point", but inappropriate.

How can I tell them that yeah, I realize they are chubby, but I find them attractive?