"I've got no willpower around it"

At some point in most conversations about sugar, someone says that they simply have no willpower. If there are biscuits in the house, they'll eat them. They've tried to resist and failed many times, and they've concluded that the fault is in them.

I'd like to offer a different reading of the same facts. You've been running a contest between a person and a tin, several times a day, under conditions that favour the tin, and you've blamed yourself for the results.

Look at the conditions. The tin lives on the worktop next to the kettle. You visit the kettle six or eight times a day. Each visit puts the tin at your elbow at the very moment you've stopped work and are waiting for something. You don't need any desire for a biscuit at that moment. You only have to not resist, eight times a day, every day, and sooner or later you will.

Researchers at Cambridge have tested how much position alone matters. Jennifer Hunter, Gareth Hollands, Theresa Marteau and a colleague ran two experiments in which volunteers sat at a table with a bowl of an unhealthy snack on it. For half of them the bowl was twenty centimetres away, and for the other half it was seventy centimetres away. That's still on the same table, needing only a slightly longer reach. In the larger experiment, with 246 people, about seven in ten took some of the snack when the bowl was near and under six in ten when it was far. In the smaller one the gap pointed the same way but was too small to be sure of. Some volunteers pulled the far bowl closer, and when the researchers set those people aside, the gap widened in both experiments. In the larger experiment, half the volunteers were given a distracting mental task designed to use up their capacity for self-control, and it made no difference to the result. Fifty centimetres changed what people ate, however much self-control they had to spare.

If half a metre of table does that, think what a tin beside the kettle does over a year. Then think what would happen if the biscuits were in a high cupboard in the utility room, behind the flour. You're not forbidden to go and get one. You just have to decide to, fetch the step stool and move the flour. Most of the eleven o'clock biscuits in your life wouldn't survive that much deciding. They were eaten because they were beside the kettle, and not from any strong wish for them.

The same goes for the chocolate bar in the desk drawer, which you bought in advance for the three o'clock slump. Buying it made the decision in advance, on a full stomach in the supermarket. The person who opens the drawer at quarter past three, tired and low, is only carrying it out.

There's a second piece of evidence that the urge itself is more manageable than it feels. Adrian Taylor and colleagues at Exeter took regular chocolate eaters who'd gone without for a few days and had them either walk briskly for fifteen minutes or sit quietly. After the walk their urge to eat chocolate was lower, even when they were handed a bar to unwrap. In a follow-up with seventy-eight regular chocolate eaters, people worked at a computer task with a bowl of chocolates beside them. Those who'd walked first ate about half as much as those who'd rested, an average of roughly fifteen grams against twenty-nine. Nobody had told them to hold back.

That matters for the willpower story. If the urge were a fixed force that you either resist or don't, a walk wouldn't shrink it. It rises with cues, tiredness and sitting still, and it falls when those change. It's a passing state, and you can let it pass without obeying it. Most urges for a biscuit, left alone, are gone in about the time it takes to make the tea.

Remember too the finding from chapter 6. The people with the firmest intentions were the ones most undone by a good excuse. Trying harder against a well-placed tin with a good story attached to it doesn't work. Moving the tin is more effective, and once it's moved you won't need much willpower.