So then, why do we measure our progress by how much we weigh? Why do we step on the bathroom scale and hope that those numbers will be lower than before? You see, our weight is affected by more than just how much fat is on our body. Some other factors include water, muscle, glycogen, and obviously if we have eaten anything earlier or used the bathroom lately.Our water weight fl Overnight lean keto uctuates constantly. For instance, when we exhale water vapor comes out. When we sweat, we are sweating out water. There are also many more factors that can affect the amount of water in our body. Water is what usually causes those random gains or losses of a pound or two in weight that can make you happy or sad. It is almost physiologically impossible to lose a pound of fat in one day.