Not only did they have to break a strongly ingrained habit but also a potent addiction. They experienced real drug withdrawals. But their conviction was strong. In a short time they were nicotine free. It became relatively easy not to smoke.
Food can take a similar route.
At first it may be hard to refuse the extra dessert. It may not be easy to go out for that first walk around the block. But soon, smaller portions of food become sufficient to quench culinary desires. You may even begin to look forward to your walk. And you will begin to look and feel better.