One more question ... I've glanced through EFS, and maybe haven't looked close enough yet, but I didn't see anywhere where he recommended weight training. I think it's super important. Could I substitute some weight training for the cardio?

I don't know anthing about EFS and wouldn't presume to guess about the program, but I can tell you on the FSD weight training doesn't come into play until P3 I believe. The reason for this is ostensibly that muscle weighs more than fat. If you start weight training at the beginning of a diet, you will not lose as much weight or possibly gain some. Even though this is healthy (and trainers will tell you the most efficient way to get in shape is to diet and lift concurrently), people pushing diets will advise holding off on the weights so you see results on the scale (which is what most people equate success with) rather than in body fat %.

That makes sense. I wonder if I could just add it in anyway ...

There's no reason you can't if you do it properly. Another issue re: the FSD is the lack of protein in the early phases. Anyone who has spent a millisecond in a gym knows protein fuels your muscles -- but that's honeslty an issue that won't have a substantive impact on the fitness we're all dealing with. Nobody is trying to get huge (just the opposite) and not taking in protein after weight training shouldn't (I'm obviously not a doctor) have a negative impact. The type of weight training applicable to fat loss is low weight and high reps (something like 4 sets of 15) in a circuit system to maximize heart rate and metabolism. If you go into knowing the numbers on the scale may be deceiving at first it's all good. On the plus side, your body fat % will be drop quicker (your clothes will be looser). So strap it on and get in there Hulk!!!

I'm in Cycle 3 of the EFS and the only exercise stated in the book is cardio. However, you are allowed to do more exercise than required so if you followed the daily cardio requirements I don't see why you can add weight training as well.

Yeah I saw that also and think it may have more to do with results on the scale and hyping the diet -- basic physiology that you gain weight when you lift so actual weight loss (vs lowering body fat %) would be less dramatic and not as good for book sales. Just a theory and love the program but still a curious detail.