"I wasn't really paying attention"

Think about where you ate your last five meals and what else you were doing. For many people the honest list is a desk with email open, a sofa with the television on, a kitchen counter with a phone, a car. Eating is something that happens while the attention is elsewhere. You look down and the plate's empty, and you have only a faint memory of the food.

This isn't a belief so much as an explanation people give afterwards. It deserves a chapter because a great deal of the extra happens here, out of sight of the person doing it.

A pooled analysis of 24 experiments looked at attention and eating. Eating while distracted, by television or a game or a task, raised how much people ate at that meal by a moderate amount. It had a larger effect on how much they ate later in the day. The authors' explanation is memory. If you weren't attending to the meal, you don't remember it well. Your sense of how much you've eaten today is part of what governs your appetite later. Other experiments in the same review support that. When people were helped to recall a recent meal, they ate less at the next one. When people were prevented from seeing how much they'd eaten, they ate more.

So distraction hits twice. At the meal, you miss the faint signal of enough, because nothing in you was listening for it. Later, you're hungrier than you should be, because the meal never properly registered.

You may be bracing for an instruction to eat in silence, contemplating each raisin. I'm not going to give it. Mealtimes are for talking, and a film with a bowl of pasta on your knee is a fine way to spend a Friday. I'd also note a result from the same review that works against the mindfulness enthusiasts. Simply telling people to be more aware of their food as they ate didn't reliably change how much they ate at that meal.

What I'd suggest is smaller and I think more realistic. There are two moments in a meal when attention earns its keep. The first is the opening few mouthfuls. That's when the food tastes best, as chapter 3 showed, so it's the part most worth being present for. Look at the food, taste it, and let it register that a meal is happening. The second is the halfway pause from chapter 5. For those thirty seconds, take your eyes off the screen and ask the question. The rest of the meal you can spend talking, or watching whatever you like.

There's one kind of eating where I'd go further, which is eating from the packet. Crisps from the bag or biscuits from the sleeve give you no plate to look at and no halfway point, and you can't see how much has gone. It's the condition from the experiments in which people couldn't see what they'd eaten. The fix takes ten seconds. Put what you want in a bowl, put the packet back in the cupboard, and sit down with the bowl. If you want more afterwards, you can get up and fetch it.