Body Shock: Half Ton Man (C4)

Megastructures (five)

SIZE does matter whether you're eating yourself to death or building an artificial island resort so big it can be seen from space.

Body Shock subject Patrick Dueul looked liked something out of a horror film when we first saw him - an enormous mound of quivering flesh and fat with a tiny human head stuck on top.

The documentary never really explained how he was allowed to reach this dreadful state. He weighed 76 stone, his weight was in danger of crushing his vital organs and he was drowning in his own fluid as it seeped out of his body and saturated the sheets.

Saying he was always hungry, ever since he was a child, wasn't a satisfactory answer to his appalling state. He was married (although wife Edith said the marriage was never consummated) but hadn't left the house for seven years. They had to take down a wall to get him to hospital.

Even more shocking was discovering he was still alive and half his previous weight. But Body Shock wasn't just a freak show. The appearance of the heaviest woman in history, US fitness guru Richard Simmons and an obesity surgeon contributed to the debate about why people become so enormous. It may be in the genes or a psychological thing. Common sense is the remedy - eat sensibly and exercise, which is all very well but who can't find an excuse to abstain from both, some or all of the time?

Long-term successes are rare among super-obese people who've slimmed down, illustrated by the sad case of Michael Hebrankco. Seven years after appearing on Wogan's TV show to show off his new slim look, he'd "slipped" and had to be forklifted on to a stretcher. He was over 70 stones. Today, he's a wreck of a man, still struggling to stop overeating. Patrick Dueul, on the other hand, is down to 35 stones.

Palm Island, a man-made resort built in the shape of a palm tree in the Arabian Sea, is part of Dubai's bid to boost its finances when its oil runs out. Mass tourism is seen as the way to keep the economy afloat. Megastructures showed that keeping Palm Island - with its luxury villas, hotels and shopping malls - afloat was a tricky business. Building it only from natural materials, sand and rock, meant major headaches for designers and construction engineers. They even had to find the right kind of sand six miles out to sea, taking eight months to make it stable enough to be built on.

If they haven't got it right, the whole structure could be washed away. What a pity that excess fat can't be got rid of the same way.