I'm not fat-phobic, because that would suggest I have a fear of or am repulsed by fat people. Quite the contrary. Fatness does not bother be in and of itself. What bothers me is what is says about that person.
Fat is not skin color or sexual orientation, which are adaptive traits of evolution or a combination of genetic traits. Fat is not a (positive) evolutionary trait. Fat is not a natural trait. While I'm sure there are genetic predispositions to being overweight, overweight in and of itself is not what I regard a disorder, so much as a failure of will. Whether you have high or low metabolism, have a propensity to store fat or burn it, you cannot get around the inexorable mathematics that weight is a function of caloric input minus caloric output. You burn more than you take in, you lose weight, you take in more than you burn, you put it on. Simple as that.
I used to be a big chubby and you know what I did? I took up running, and slimmed down. I watch what I eat, and monitor the kinds of things I intake, and when. I do not accept that I'm somehow predestined to be fat or thin, rather that I have the power to control it. It takes hard work, determination, but it is possible.
And so when I see a fat person, especially someone who was once thin but now fat, I see many things beyond simple girth. I see a person who has given up in a way, who is no longer maintaining them self.
I have to have someone who is active, and enjoys the outdoors as I do, and you won't get this with a fat person. I can't waste my time with someone who gets out of breath walking up stairs, when I run 10 milers in 60 minutes flat.
I want someone who is focused on their work, not thinking about that next Big Mac. I want someone who wants to be sexy for me, just as I would do my best to be sexy for that person. To many people take marriage to mean they can let themselves go, and if I ever find that girl willing to marry me, I'm gonna do my damndest to be the best mate to her.
And ultimately, I want someone who will live a long happy life with me. And with a fat person, even if they are somewhat active, are simply at a greater risk for all kinds of health problems. I don't want to bury a spouse at 50.