I do believe in the concept that when calories in are less than calories out, you lose weight. What I don't understand is how a person can eat 1200-1500 calories per day for two weeks and not lose a single pound. I just don't understand where the energy the body is using is coming from. It's not coming from the food you are eating, as you are eating less than your body uses for those days, and it's seems like it can't be coming from your fat or even other tissues, as using that energy, would result in losing some weight. So...if it's only about the number of calories eaten, how on earth can you go weeks without losing?

As a side note, I totally get how daily fluctuations work, especially with water and salt intake. I drink about 10 lbs of water a day, if I have a little extra salt that day, of course my body will keep some of that water around to dilute the salt. Really, it's just the plateau's that I really struggle to get.

Other thing I don't understand is how someone can eat over 4000 calories a day and not be gaining any weight. What that tells me is that all of our bodies are different and digest/consume/burn calories a little different, but for any given person, the calories up or down is what makes the difference. Of course I could be wrong.