Going the extra step, who's to say something at home isn't causing the eating?
As a kid, my sperm donor used to take semi-naked photos of me, to show me how fat I was. This would now be seen as mental cruelty among other things, as I knew I wasn't as slender he wanted me to be, but I used to play rugby (as previously said), used to be in the swimming pool more than the lifeguards (competition training - NOT lazing it up), cycling to and from school, swimming and anywhere else my bike took me, and still those photos were taken.
Those photos were found recently and my family all agreed that this shouldn't have been allowed to happen, because they had the adverse affect, I ate more to comfort myself.
In those days, Social Services were slow to react, slower to care, and always reversed when they met the sperm donor.
Without going further into things, as I entered my teens, I continued cycling, stopped playing rugby, but still swam in competitions, did triathlons for my cadet unit and continued to cycle everywhere, but those photos were still taken.
Never once did my sperm donor stop and look at both what he was saying and doing, and the amount of things I was doing, he could only see what he disagreed with. A bit like yourself.
Everyone is entitled to their opinions, of course, however sometimes they need to be kept to yourself. Think the old saying "If you can't say anything nice, don't say anything at all".
Additionally, I think that only those who you won't take offence to (friends and family), should point out your weight gain, or any other foibles, otherwise they're likely to be met with strong comments or even worse back. I'd never comment to someone I didn't know about their smoking, drinking, drug habit, or anything else, because it's their business and someone else would've made the same observation.
Also, those saying about weight costing the NHS. Smoking, Alcohol and Drug abuse also cost the NHS, but you're failing to mention those services.
If at any point has my weight cost the NHS, I feel I've paid for it. I pay into the pot with my National Insurance contributions, it's almost like the mentality of "I pay road tax", so please drop those comments, only time they're valid is for the people who have never contributed by not working a day in their lives, and that's a whole different subject matter.
Might be worthwhile you stopping and thinking next time before pointing out the obvious to someone unknown.
