I certainly wouldn’t say everyone has experienced weight loss… I dropped two kilos in the first 2-3 days, but gained those back after a week or so. I have on occasion lost a little (~1-2kg) depending upon what I ate that week, but with the exception of those few blips, I have maintained exactly the same weight throughout. I was really worried before starting, so I made a chart and weighed myself at least three times a day, and after two months of doing this, I realized that my weight never fluctuated more than a few kilos from what it was originally (I even gained a small amount of weight at one point). Since then I just weigh myself from time to time out of curiosity, but there’s been very little change. (This was a little disappointing, since I thought loosing 5-8kg would make for a very nice “silver lining”)
This diet has quite a few items on it that are calorie heavy (I eat more fats and oils than I used to… “good” fats, mind you, but calories are still calories). Plus, I think everyone’s body reacts differently to a change in diet. Mine just happens to maintain a very tight weight range, regardless of diet. For you, it seems that there’s some aspect of this diet compared with your old diet that made you put on a little weight.
If it really bothers you, however, you might also want to look into what else has changed besides your diet. For instance, are you exercising less, or eating at different intervals? Are you more stressed, or getting less sleep? Etc. etc. Heck, it might even be a supplement or medication you’ve started taking, or it could be that you packed on a few “winter pounds.” If weight change were easy to understand, there wouldn’t be a multi-billion dollar industry surrounding it.