I used to eat in case I got hungry later. So without ever feeling even slightly peckish.
I've lost 8 stone since then. Allowing myself to be hungry was one of the most significant factors in the early days of weight loss. I decided two things:
(1) I would only eat at meal times. I would eat as much healthy stuff I wanted at meal times, so was happy to allow myself big portions. But these must be breakfast, lunch or dinner. No snacking between meals whatsoever.
(2) I would only eat a meal if I was hungry and would stop when I wasn't hungry.
When I was very big, I discovered that I could miss both breakfast and lunch without being hungry. I'm not advocating this long term, but when you have vast, VAST amounts of body fat your body can manage easily by burning the fat stores it already has. This may not work for someone with 4 or 5 stone to lose, but morbidly obese people need not feel they "must" eat.
Realising how infrequently I needed to eat was a massive revelation to me. As time and weight loss progressed I started needing lunch. But this was because I recognised I needed to eat lunch rather than just eating just because society said I should.
I continue to not usually eat breakfast (my BMI is now healthy). I tend to find I'm thirsty in the mornings so drink a litre or two of water/squash and several coffees through the morning. This is despite the fact I run around 10km every morning, 7 days a week.
As a daily runner, there's another load of society expectations about food I have to dispel. "You need to eat more when you're doing that much exercise". No, I don't. I listen to my body. "You need more carbs with that much exercise". No, I don't unless I'm doing a particularly fast or very long run, neither of which I do very often.
I think people give this bad advice to make themselves feel better. They think they'd want to eat more if exercising, so project onto me when I don't. They'd want to eat loads of bread and pasta if running, so project onto my hummus and veg sticks lunch. I also get loads of "you need to be careful about anorexia" which is especially insulting given I'm only 1/2 stone within the top end of healthy BMI. All projection I think.
But back to topic. Learning to listen to your own body and not being scared to not eat when society says you should is a big revelation.