Well I'm fat and I'm just living my life, some days it's my best one and others it's a complete shit show, and I imagine that's the same for most people too, regardless of their weight.
I think though, that there's things that are 'in fashion' and things that aren't, and being overweight is not fashionable, with people commenting on the cost to the NHS as a reason for their worry.
I was slim and fit in my younger years, but I drank a lot of alcohol. I now have a bum knee because I injured myself whilst drunk, but that was funny, I was such a one, no one was telling me that I was out of order because I'd cost the tax payer money with my choices, but being overweight people naturally assume that it's because of that, I would agree it's not helping, but it's not the cause, the cause is an injury and a predisposition to arthritis, but because I'm overweight it's all about the strain I'm putting the NHS under.
I'm losing weight steadily and it's helping, but even if and when I hit my ideal weight, the problem won't go away.
Alcohol costs just as much I'd guess, if not more than obesity, but you can't generally see the results of over indulgence in alcohol immediately as you look at someone, and drinking alcohol is 'fashionable' even though it costs health wise, it costs society wise. Things like wine o'clock and the way people behave when it's restricted (for health and social reasons) tells you that - and I'm not just talking about a bottle of cider in a brown paper bag. It's in every layer of society yet mention it and you're met with cries of 'anyone who drinks more than a thimble full of sherry at Christmas is considered an alcoholic on MN'.
I've yet to see a fight break out because people ate too much cake and lost their reasoning skills, I was never shouted at through a car window for being a piss head though I have been shouted at for being overweight.
Restricting what someone can do because they're overweight is seen as concequences, restricting someone because they've had too much alcohol (refusing entrance, further service etc) is seen as being over controlling and power hungry.
Both cost the NHS and other services money and time, the difference is that overindulgence in alcohol is 'cool' and so doesn't attract the same level of criticism as overindulgence in food.