MommyDoc's Journal, 14 April 2013

Protein pushes water out of the cells, so if you cheat just a little with carbs, you will see an instant gain (from the cells retaining water again). That's the sucky thing with Atkins. You lose fast, but gain it back fast if you aren't careful. It could also be sodium or one of many other factors. Just get back to plan and keep going.  

just water gain it will do away in a couple days just try not to cheat to much if its a big issue for u. we are all not perfect its hard not to want to cheat dont beat your self up