The decision

You've got the argument and the method. What's left is to decide, and I'd like the decision to fit in one sentence.

I put what I'm going to eat in a bowl, I put the packet away, and I eat it without a screen.

Three parts.

The first is the bowl. Whatever you'd call a few, in a cereal bowl, with the packet clipped and back in the cupboard before you sit down. Seconds allowed, by getting up.

The second is the shop. Buy the unit you'd eat. Small bags, small pots, the sharing bag only for sharing. Vary the partition so it keeps working.

The third is the two minutes. Screen off, or eyes down, for the bowl. Taste the first one. Notice the tenth. Then the programme.

There's a form of planning that helps with rules like this, and it's been tested many times. Peter Gollwitzer and Paschal Sheeran reviewed ninety-four studies of it in 2006. You decide in advance what you'll do and when, in the form "when this happens, I'll do that", and people who plan that way follow through much more often than people who only hold the intention. So write three.

When I open a packet, I'll pour a bowl, clip the packet and put it back in the cupboard before I sit down.

When I'm in the shop and reach for a sharing bag, I'll pick up the multipack instead unless there are people to share with.

When I sit down with the bowl, I'll leave the screen off until the bowl is empty.

What to expect. This is my expectation and not a finding. The first night the bowl will feel small and slightly ridiculous, and you'll finish it and consider getting up for more, and about half the time in the first week you will, and that's fine, because the getting up is the partition working and the second bowl is still smaller than the run. By the third night you'll notice the taste of the first crisp, and notice that you'd stopped noticing it. Around the end of the first week the getting up for seconds will have mostly stopped, because the wanting was satisfied in the bowl and the walk to the cupboard is enough to tell you so. The list from chapter 1 will have a week of bowls on it and no bottoms. By the third week the small bags will be in the cupboard and the sharing bag won't, and the sofa will have a cereal bowl on the arm most nights and a person on it who's had crisps and knows it. You'll still fancy something at half past eight. You'll have it. It'll taste of crisps.