Is anyone aware of a minimum amount of time that there should be between CMs?

I missed breakfast today (sort of, explanation later). By the time I was ready to eat it, it was 11:00, and I usually have lunch at noon. I thought that 2 CMs within an hour or so was too close together ... but I can't recall any guidelines from the book. Anyone have any information?

In the end, it was all a moot point. I had brought celery and cream cheese for breakfast, and for lunch I bought a salad consisting of some romaine lettuce, 3 slices of cucumber, some bacon, and some chopped chicken with mayo. I took less lettuce and cucumber than usual, and then had my 3 stalks of celery and cream cheese at the end of my CM. I think that my carbs were still less than 4, but I am wondering if people who have only one CM can have a larger CM than if they had 2 CMs, provided they keep the carb count below 4.

Opinions, please!