To make lasting change you don't' just change the behaviour i.e. stop eating too much...
You need to understand that the behaviour of eating, or smoking, or drinking etc is a behaviour and isn't who you really are.
In life we have the logical levels of change which are
Identity - Does changing reflect who I really am?
Values and Beliefs - Why make the change?
Capability and Skills - How do I change?
Behaviours - Change what?
Environment - Where to change?
Now most people who try diets are trying to change the environment and the behaviour i.e. they may stop going to their local restaurant, they may avoid food in the kitchen at work and they will try and stop overeating.
But most people don't look up the levels of change, they don't look into how they really make change (capability and skills), they don't look at why they want to change, what it is they believe about themselves and their world which means they have got overweight in the first place. They don't look at who they really are, what they really want with their lives, and ultimately what life is all about.
We get stuck in the 'I need to lose weight' problem which means you are looking for a solution at the bottom of tree of change, and by changing the behaviour i.e. stop eating for a while won't give you lasting slimness if you don't truly believe you deserve to be slim, or that you actually haven't got a really good positive, forward thinking reason to both get slim and then moderate your food intake to stay there.
So read back through the logical levels, when you come up with your diet plan then are your really looking high enough up the levels of change to make a difference or is it just Monday so you are going to try to do another diet?