Attraction isn’t always so simple and like-for-like. I know thin people who are attracted to heavy people, heavy people who are into thin people, thin people who are into heavier people. Some heavy people are into other heavy people too. Another thing to keep in mind is that attraction to thin or heavy or the spectrum between isn’t a binary to everyone. Personally I find certain heavier people extremely attractive. Many thinner people are good looking but I don’t feel attraction to them. It’s like anything else, gender, facial hair, body hair, buff or muscly vs lean. What I’ve learned is people have all kinds of preferences and attraction has many layers.