This is inspiring. I had the same problem, I diet and lose weight and regain thereafter. It's like a yo-yo system. One step at a time, I think it is a good idea. I always thought that losing weight fast is ideal but I was wrong. And, I can vouch the effects of it.
It will definitely take time and commitment to change. He did this in four years which can be considered pretty long. It won't be easy but it will be worth it to see the changes. i love the idea of going slowly, one step at a time.