"Everyone slim weighs every day"

You picture slim people as people who keep an eye on it, and keeping an eye on it means the scale, and so daily weighing looks like the habit of the people you'd like to be. It's an understandable picture. It's also mostly wrong, and where it's right it's right about a different group from you.

Start with how common it is. In Quick's survey from chapter 9, weighing a few times a week or more was reported by eighteen per cent of young women and twelve per cent of young men. That's a minority, and it's a minority that, in the same survey, had more depressive symptoms and lower self-esteem among the women and lower body satisfaction among the men. Slim wasn't the defining feature of the group. Weight concern was.

Now the other side, because there is one. Pacanowski, Linde and Neumark-Sztainer reviewed twenty papers on self-weighing and how people felt, and found the results split by who was being studied. Among women and younger people, frequent weighing went with worse mood, lower self-esteem, worse feelings about the body and more disordered eating. Among overweight adults who had chosen to seek treatment, it went with no harm, and sometimes with benefit. Lori Klos and colleagues found the same split by sex among 268 students. Frequent weighing in women went with preoccupation about being overweight and concern about shape. In men it went with an interest in fitness and feeling better about the body.

So the true version of the belief is this. Some people weigh daily and it works for them, and they tend to be people who've decided to change something, are in a programme or something like one, and read the number as a point on a chart. The picture of the slim person calmly noting the figure and getting on with the day is a real person. It's just that the calm comes from the chart, not the step.

Which group are you in? Not by weight, by what the number does. If you got off this morning and the number set the mood, you're in the first group whatever you weigh. The research says the habit is at best doing nothing for you and at worst doing the things in chapter 9. The people it helps aren't feeling the swing. That's the difference, and it's the whole difference.