If you look in the Appendix of the book you will note that the results for those skipping breakfast were actually better than those who ate breakfast. Other research would back this information up as well, as well as other programs like Intermittent Fasting. Two of the reasons Tim supports the idea of eating within 30-60 minutes of waking are, the longer you fast the greater a chance you will give in to cravings and getting in the early dose of protein will help prevent the 3:00pm fatigue that many of us experience. There is a lot of talk about it kick starting your metabolism, etc, but if you do some research there are very few studies to support this idea, and those that do seem to come from Epidemiological Studies rather than Clinical research.
With that being said some people find they experience much greater weight loss by eating the 30g within 30 minutes and some find better results with IF. It is a matter of experimenting, like most everything else with Slow Carb. Bodies are very different. There is a lot of new research into how different blood types play a role, how different body types (endomorph, ectomorph, mesomorph) play a role, not to mention vary degrees of sex hormones, geographical influences, etc. Fat storage is not a clean cut issue by any means and the research is just starting to scratch the surface.