I think the above questions are very relevant. Even on a vlcd diet I have weeks when I lose nothing. Now you are on Paleo your carbs are still low so you should not really be gaining food related water weight, but your hormone levels can impact on water weight. Also the actual bulk of the meal will take a little while for your body to digest, depending on your personal digestive system. Therefore, if you are on the first few days of this I would not worry, it will soon shift. If in the first 2 weeks and not gaining I would still not worry. If you are really close to goal weight then I'm afraid probably it will take a bit longer to drop the final few pounds. Take care, you will get there!