I'd expect an 853 road frame to be quite flexy so not a very efficient ride compared to a carbon or aluminium frame. Also they're likely to rust up during winter road usage due to salt on the roads which is not much of a problem for aluminium and less so for carbon.
Yes eating too much fat and crap coupled with no exercise,I bet they have X Boxs at home and sit playing those rather than doing anything physical.
Perhaps instead of taxing fatty foods we'd be better off bringing in a law whereby anyone of a certain age who goes over a certain weight limit based on a percentage of body fat should be sent to a fat camp,a bit like a prison sentence but a sentence for being fat and lazy, term to be decided on how much they exceed their maximum allowance for body fat, levels to be pre-determined by the NHS. I can just see it now, some lard ass trying to do a chin up in camp and failing to haul their ass up with a drill instructor screaming 'get up there you fast b@st@ard!' Then don't let them out till they drop below the acceptable limit.
Well that fat family don't look like they live in a des res suburb of Dundee, probably not too well off so how the the hell did the family afford to buy the amount of food required to get the children so fat in the first place?