"I wasn't paying attention"

You'd say this as an excuse, in a slightly embarrassed way. The programme was good. You weren't concentrating. It just happened.

I'd say it as the mechanism, without the embarrassment. Not paying attention isn't why the run happened despite you. It's how the run happens, and there's good evidence for how much.

Robinson's review from chapter 4 had a second finding, and it was the largest in the paper. When people ate while distracted, by a screen or a task, they ate moderately more at the time. But the bigger effect was later. Distracted eaters ate more at the next meal too, by a margin about twice the size. The distraction didn't just let the hand run. It seemed to stop the eating from registering, so that the body and the memory didn't count it, and the next meal was eaten as though the crisps hadn't happened.

Hetherington and colleagues, in 2006, put thirty-seven people through four lunches, alone, alone with a television on, with strangers and with friends. Eating with the television on raised what people ate by fourteen per cent over eating alone. Eating with friends raised it more, by eighteen per cent. Eating with strangers didn't raise it, which the researchers took to mean that the effect isn't only distraction, since strangers distract too. But television alone, with no company, added a seventh to a meal. It's a small study and it's about lunch, not crisps. The direction is the one the review found across twenty-four studies.

Zlatevska's meta-analysis in chapter 5 had the same thread. The portion size effect was weaker when more attention was paid to the food. Attention is the thing that lets you notice the fifteenth crisp tastes of nothing, and notice that the bag is lighter, and notice that you didn't want this many. Take it away and none of that gets noticed, and the hand goes on.

So "I wasn't paying attention" is the truest thing you could say about the run. It's just not an excuse. It's a cause, and causes can be changed. Chapter 22 is about eating the snack with the screen off, for the two minutes it takes, and then turning the screen on with an empty bowl and a taste in your mouth that you actually remember.