It is only common sense that you won't be so tempted to overeat if the motivation comes from inside you and not from external pressures.
Psychology research has been nipping at the heel of self-regulation for over twenty years. One area of self-regulation research has to do with self-control as a limited resource. What this means is that your self-control can become depleted and once depleted, it will then have to be renewed.
So what do depleted self-control and being tempted to overeat have to do with one another? As it turns out, if you feel forced to stop overeating, you will have to exert more self-control than if you decide yourself that it is important for you not to overeat. You will need more self-control if it is not your own idea. Exerting a greater amount of self-control leads to your self-control being depleted faster.
The moral of this story is that your ability to resist temptation depends on how self-motivated you are to resist it. We all knew this. No news here. But this is an explanation of why this is so.
When the motivation comes from inside you, you simply don't need as much self-control. This means that you can regulate yourself more easily, probably longer, and even more efficiently and effectively. With self-control in place like this, you will have sufficient mental energy to tap into your long range weight loss goals,and use them to further your resistance to temptations.
Scientifically proven diet information, especially if it jives with common sense, is something to carry with you at all times.