"I can't trust myself without rules"
Under the last chapter there's a fear, and it's worth its own space. Without rules, you'd eat everything. The rules are the only thing standing between you and a free-for-all, and you know this because whenever a diet ends, that's what happens.
Look at when the free-for-all happens. It happens after the diet ends. It's the Friday takeaway after the Thursday write-off, and the fortnight of eating before the next fresh start. In other words it happens as part of the cycle, in the half of it that follows restriction. You've never seen what your eating looks like when there's been no restriction for a month, because there's never been a month without a diet or the aftermath of one. The free-for-all isn't what you're like without rules. It's what you're like after rules, and those aren't the same thing.
In my experience of people who stop the cycle, and this is observation rather than a finding, the first two or three weeks off diets are uneven. Some meals are larger than they need to be, because the body has been through a lot of fortnights and hasn't yet believed that food isn't about to be taken away again. Then it settles. Meals become meals. The biscuit becomes a biscuit. The eating that felt like a flood turns out to have been the eating of a person who'd been restricted, and once the restriction stops being threatened, it stops.
What holds it together isn't rules. It's structure, and they're different. Three meals a day at roughly regular times is structure. It says when, not what, and it doesn't forbid anything. The NHS puts "don't skip meals" on its short list because skipping is what produces the snacking, and regular meals are the opposite of skipping. You can trust yourself with structure, because structure doesn't set up the write-off. There's nothing to break.
A reader will ask about the cupboard. If nothing's banned, what stops the biscuits in the cupboard from going in an evening? Two things, and neither is a rule. The first is that you've had dinner, at seven, of a size that satisfied you, and a person who's eaten dinner wants a biscuit or two and not a packet. The second is that the biscuits aren't going anywhere. They'll be there tomorrow, and the day after, and nobody's about to take them away, and a biscuit that isn't about to be forbidden is a biscuit you can leave. What empties a packet isn't the absence of a rule. It's the presence of one, about to be enforced from Monday.
So the belief is right about one thing. You need something. It's wrong about what. The something isn't a wall around the biscuits. It's a meal at one o'clock and another at seven, every day, with nothing forbidden in between.