Obesity is an ever-expanding problem. In Powys Street in Woolwich, branches of Greggs the bakers are stationed every 50 yards. It's a tragedy. Hence the Government's Change4Life campaign to promote healthier living, especially to kids. This advert, animated by Aardman Animations of Wallace And Gromit fame, shows our plasticine ancestors hunting mammoths and biffing dinosaurs for food. Cut to the present, where we only have to haul our butt three yards from PlayStation to dining table to chow down. However, as an interior depiction of the human body shows, this inactivity means that fat is operating insidiously inside us, storing up trouble which could prove fatal. Cut then to an idyll of healthy living, of days filled with sit-ups, playing on swings and munching apples: "Move more, live longer." Now, I'm all for people living longer and moving more, some of them as far away as possible, but... hmm. Quite apart from buying into the Creationist myth of humans and dinosaurs co-existing, this ad is strangely reluctant to show that obesity will make you fat. Whether hunting, loafing on sofas or exercising, Aardman's plasticine people are depicted as exactly the same size throughout. Obesity is presented only as an interior, not exterior (or posterior) problem. Yes, they're trying to avoid stigmatisation of the portly. But if you're trying to highlight the dangers of overeating and under-exercising and not prepared to face square-on the fleshy reality of multiple chins and enormous arses, you make it that much harder to shock the kids skinny and get them to step away from the pie. Don't sell shares in Greggs yet.