I'm no expert, but these have worked for me:
- Drink a glass of water before a meal, your stomach will get full sooner
- Use smaller dishes - the risk of accidentally putting too much food on your plate will be reduced and you'll maybe feel psychologically more satisfied having eaten "a full plate of food"
- Stop eating when you're full, don't stuff yourself
- Fiber-rich whole grain products tend to digest slowly so you'll not get hungry too soon again
- Every time you're about to eat, ask yourself whether you're actually hungry or just bored/used to eat at that time of the day/greedy for that particular food. Becoming aware of the amount of "unnecessary" treats you have each day will probably help to lessen them.
- Not eating when you're hungry can result in gormandising
- Only shop groceries when you're content, it's less likely you end up buying chocolate and chips