I know there's an obvious Darwinian explanation for this, but the continual press coverage concerning Britain's slippery slide into obesity and gloomy predictions that we're becoming a nation of gargantuan salad dodgers has made me think about what the evolutionary benefit is of being predisposed to liking the very foods that in quantities are bad for you (ie. those high in sugar and fat).
Sugar, being pure carbohydrate, is obviously able to provide a temporary burst of energy, which is undoubtedly handy when running away from lions or something. Too much sugar for the metabolism though, turns to fat, and by storing an excess of saturated fat while scampering around the plains of the Serengeti, you'd be less likely to escape predators and would become a victim of natural selection, meaning your lardy genes wouldn't be around to continue to produce similarly rotund offspring. So I'm guessing here, that Man, as an ape, needs a bit of fat to sustain him when times are lean, and a bit of sugar, to give him bursts of energy. Everything in moderation.
It seems to me though that there's a good argument that obesity is simply the way it's meant to be. Brain power and advanced cognitive thought processes have resulted in civilisation and convenient solutions to primeval problems. The next time me and my wonderwife are gorging ourselves on a fat-saturated Pizza Hut all-you-can-eat-buffet, I'll be taking solace in the fact that our ancestors have earned us that right.
We should be allowed to get as fat as we like. It's not our fault that our ancient hairy brethren had sufficiently developed brain power to walk on two legs, use rudimentary tools and open fast-food restaurants with 'bottomless' Coke and Ice Cream Factories. Brain development is no less of an evolutionary miracle than opposable thumbs or the capacity for compassion and we modern humans are sufficiently far up the evolutionary ladder to reap the benefits (though looking at some of the individuals who work in Pizza Hut, some may still have a few rungs to go).
It's not all bad for the other apes though. At least they haven't got a simian Gillian McKeith scowling around the jungle floor examining monkey shit and tutting at the presence of undigested nuts and berries.