From Alan McConville
The controversy regarding the Atkins diet is topsy-turvy. You report research suggesting that it works because followers simply eat less (19 March, p 12). But the real conundrum is: why do carbohydrates make you fat?
Repeated carb-rich meals make you tired, hungry and ultimately fat, unless you count calories and suffer. But why should humans respond in this way? Probably because that is how our hunter-gather bodies are programmed to respond. Ten thousand years ago large quantities of carbs appeared briefly every year, coincidentally, more often than not, at least for Europeans, just before a winter famine. The optimum survival response in this situation is to eat as much of the abundance as possible before it rots or someone else eats it. For the rest of the year, high-quality carbohydrate was scarce and we lived on leafy plants, ants and meat. It wouldn’t have paid to be too fat, lest the meat bit get away.
When we became farmers the effects of storing carbohydrate from grains was offset by lots of work. Now many people don’t really work, and even the recommended balanced diet probably contains enough carbs to trigger the “get fat, winter’s coming” response – all year round.
Rhode St Genese, Belgium
