This served us well for generations when famine was a real danger, but the efficiency of modern, industrialised food production has turned this biological impulse into one of our deadliest enemies.
In the developed world, it is feast, not famine, that is the big threat to health, particularly as highly processed and high-calorie food is often the cheapest, despite its nutritional shortcomings.
And it is perhaps snacks, so apparently appealing, so quick and easy, that take the inglorious crown as the worst of the worst. Enter almost any shop that sells food and you are likely to find yourself being tempted by an array of sweet and savoury treats.
According to a new poll by the charity Nesta, one problem is that, while many people are quite good at estimating the calories in meals and drinks, we tend to be way off with snacks. For example, it found 95 per cent of respondents underestimated the amount of calories in half a sharing packet of crisps, some by as much as 300 calories.
The fightback against this commercial exploitation of some of humanity’s primal urges needs to be waged on many fronts, but greater education – about how to cook well, particularly on a budget, and healthy eating – surely has to be part of the answer. We are being cynically and ruthlessly manipulated, but knowledge is power.
By working together with those in the industry who realise there is a problem, we can reverse the rise of obesity, while continuing to enjoy what should always be one of life’s great pleasures: good food.