Originally Posted by wolfchild

The reason you're gaining weight is because your body and your metabolism is messed up from doing too much fasting and following keto diet...I think you're taking things to an extreme...When you restrict calories and fast your body interprets that as an attack and the brain starts sending signals to your body to store fat. If somebody makes a lifestyle out of it and continues to do that for a long time, eventually they come to a place where it will be impossible to loose weight, even on low calorie diets with fasting...It's best to stop following dietary fads and start eating normally.

Originally Posted by General Geoff

Then assuming your calorie count is reasonably accurate, the only other place it could be coming from is water/fluid intake and retention. Otherwise you'd be violating the laws of thermodynamics.