I dont have time right as of this moment to find a source for the fiber ?. I will look for one when I have a chance. It is much the same as the fiber in veggies/fruit slowing the insulin respones from the carbs that they contain.
As far as the the higher insulin response from the fat free cottage cheese. That is do to the lack of fats. So he by adding peanutbutter is getting much of the same result, only replacing the milk fat, with the fats in the peanut butter.
This can be good for several reasons.
-By getting the fat free cottage cheese, it is more versitile to go with the P+C, P+F meal combos many of us follow. No need to purchase two different kinds.
-You are better able to control what type of fats you are consuming. Many of us have no problem getting the sat. fat levels we desire due to the high protein diets. So with the fat free version you can pick and choose which type of fats you are getting by what you have along with it.
-The last thing off the top of my head is the protein content. The protien in the fat free cottage cheese is ~17g per 100g serving, while the regular version is ~ 12g for the same serving. So while yes, you are paying a bit more, you are getting more of the protein you are looking for.
Just a few things to ponder. When I get a chance I will look for some writing on the fiber.
Hope that helped