I don't think body size determines attractiveness. One thing that tends to irk me quite a bit is when people say "fat-and-ugly" as if it's all one word. Being one does not equal being the other. People can have extra weight on them and be gorgeous, while I've also known some butt-ugly people who are very thin! The ideal image fluctuates from generation to generation. Lillian Russell was considered a beauty queen in her time, and she was a 200-pounder.

I have considered myself unattractive at times also, but in all honesty I'm not. If I'm in the 51st percentile as far as beauty goes, then I'm "prettier than most," right? Chances are, this at least applies to you too. Confidence is the biggest factor. A change in confidence can lead to a great change in appearance. I think Susan Boyle looks a lot better now than when she first started out, and I think much of that is the boost in confidence. She probably has had some professional guidance with her grooming and personal appearance, but elevated confidence is what gives a person the push to take care of those things.

I have no idea what you do look like, but I'm betting you are basically attractive and that you don't actually look like, for example, the pig people from the Twilight Zone. Let confidence and self-esteem give you the push to take care of yourself, and that alone will do wonders for your looks. I say this from experience, because when I really hated myself and thought I looked hideous, my gloomy expression, lack of smile, eyes that didn't shine, and hair that wasn't brushed caused me to not look as good.