This probably won't be a popular response because it goes against one of the primary rules.... But I had a lot of success when I did IF until lunch. I did coffee in the morning and ate nothing until lunch. I averaged 0.8 kilograms/week doing that, without having much to lose, so I was happy. Are you not seeing results without having breakfast? Is that why you want to add it? Otherwise, if skipping breakfast is working for you, why change? The author encourages people to experiment and find what works for them!