The magic number for me was “calories per kilo”. I made a list (I’m sure you could just Google it now) of foods graded by calories per kilo, and just ate the lowest ones.

And presto: suddenly you’re full much faster, longer and you’re losing weight.

Then it was a matter of not snacking out of habit, which is MUCH harder. Of course, you can’t eat food you didn’t buy, so i really only diet at the supermarket.