I did a pulse feast on a Saturday and a cheat day the following Sunday, actually it was just a cheat meal, with a sweet bun, a small chocolate cake and a bottle of pomegranate juice. I don't think it was that much a caloric surplus than my normal diet but after a few days when I measured I went from 11% body fat, back to 12.6%, gaining more than 1kg of fat and losing a bit more than that of muscle (I have access to a very precise scanner). Maybe I should have done the opposite like stated at the article "In the defense of cheat days" by John Romaniello and had the cheat day before the pulse feast.
Maybe the increased sensibility of insulin after the pulse feast was the responsible for storing the extra calories as fat. Even if it was that the case, I think that it shouldn't be accompanied by a decrease in muscle and since I was trying for the first time Gironda's 8X8 system, maybe the lose of muscle was due to my overdoing in the workout and unrelated to the pulse feast.
I didn't have a cheat probably for 3-4 weeks, eating a low carbohydrate/high protein diet, with no bread, etc., basically what Chris Shugart says and nothing else changed in my diet besides that cheat day, so I can't find another reason besides that single event. After everything going well for weeks I thought my FFB metabolism had become a bit better in managing carbs and didn't think just one cheat would be enough to make such a change so fast. What do you think?