The Power of substitution.
We have very little control over our thoughts, they just appear for example avoid thinking of a pink elephant. Try it now Force yourself not to think of a pink elephant with a curly tail. You can't do it .It's impossible.
The only way of consciously changing a thought or of making a positive change to a habit or behaviour is to substitute another. You can avoid thinking of a pink elephant by thinking of something that appeals to you even more. Like what you will have for dinner, or that fabulous dress you saw in town (if you were me).
You can stop suffering from negative feelings -not by suppressing them but by substituting positive ones.
You can give up limiting behaviours by replacing it with enriching ones. Instead of focusing on the diet you focus on becoming fitter and healthier. Instead of concentrating on the what you are missing (chocolate cake ) you concentrate on what you are gaining. Healthy fit slim body.
Substitution is immeasurably more powerful than willpower as an agent for change.