My suggestion: use every meal as a reward for something.
Here is an excerpt from an old piece of mine, not very LessWrongish, but you may find some ideas interesting:
The Theoretical Discussion section looks into the causes of the obesity problem and expands its scope to a more general topic of addictions. Its first subsection, Hunger Recognition entertains the idea that the availability of digestion capacity may get mistaken for real hunger. Overeating is not the only bad habit that people struggle to overcome. Studying the similarities and differences among various bad habits and addictions helps us better understand their nature and fight them. Decision Fatigue subsection opens discussion on habits. Priority Bias digs into causes of poor decisions, and Commitment with Mindfulness talks about sustainable solutions.
My suggestion: use every meal as a reward for something.
Here is an excerpt from an old piece of mine, not very LessWrongish, but you may find some ideas interesting: