I have to disagree somewhat. I've never known a man to be "attracted to large women and a friendly personality". You hear about "chubby chasers" but I'd imagine it's a tiny fragment of the population. That said, skinny women are just as unattractive and unhealthy, if not more so.
I would also argue that it's not just "unhealthy and unattractive" when you are so obsese you can't reach private parts. I think it's safe to say that anything more than 20lbs overweight is unhealthy and unattractive (to most). Not to mention that once you get to be 40+ lbs overweight there are likely addiction issues that need to be dealt with.
I personally have a metabolism that stinks and everyone in my family, just about, is very overweight. I'm approx 10-15 lbs overweight and I fight every day. I haven't had cake, cookies, ice cream, sugary sodas, or anything of that kind in over 10 years. My point is you deal with what you have. You don't end up 300 lbs and then blame your metabolism. Live within your means. I believe I have an excuse as I sit in a chair all day at work, get limited exercise, and live in America where the food is as bad as it gets. Any meal I don't prepare from scratch and I have to get "on the go" is a meal that will likely make me gain weight.