Weight fluctuations?

I have been maintaining now for around 2 years, and day to day my weight would fluctuate 2, 3, 4 pounds up and down.  No big deal, that is water weight and my average was always where I wanted it to be.  Well, now things have changed and for some reason I don’t fluctuate from day to day and if I do it’s only by a half pound or so.  I’m not really complaining I would just like to know why.  The only thing that has changed is I have upped the amount of protein in my diet.  Not much, basically adding 100 grams of chicken breast with lunch and so forth.  Does anyone have a theory as to why this might be happening?

1. Maybe your BM is more regulated.  Sometimes we gain 2 or 3 pounds just based on when we have a BM.  Some people go on an irregular basis; others can get into a perfect rhythm and go almost exactly the same time of day each day.  Some people may not go for 2 or 3 days, but their body adapts to that.
2. Maybe your body combination of sodium, water has been affected by your slight protein intake.  My body water % varies from around 54% to 59% from day to day, even hours to hours on the same day.
3. A 2-3 pound fluctuation EVERY day seems odd to me, especially for as long as you experienced it.  I have fluctuated as much as 8 pounds in one day and on occasion 4or 5 pounds; but generally there are many days where my weight fluctuates very little.  I don't know how good of a scale you have, or if new batteries are needed, but maybe the scale is somehow "on" again and was "off" when you were weighing.
4. Have you changed what kind of fluids you drink, how much, how often, and when?  Have you changed your diet so that you get less or more water from fruits and vegetables?
5. Perhaps, your metabolic engine has reached its exact calorie burning apex and has now regulated your body so that the weight is consistent.

I'm using the same scale every day, it's the scale at the gym.  How do you determine your body water %?  I guess I have been drinking a little more beer now, but that's not every day.  Thanks for the reply.

I use a Tanita scale, which I readily admit is not the same as getting it checked by a professional.  However, it is consistent, even if it is off a bit.  It works by sending electrical impulses up throught the soles of the feet.  Anyway, I record the results even if they are general and not specific in nature.  These are the readings I have gotten lately for body water % when I weigh in.  56.7--57.7--54.6--56.6--56.3--55.8--52.3--57. 7--58.4--56.2--56.4--57.9--59--57.8--54.3--55 .4

Do you... or did you run more before?  My Sunday, Monday weight is always way down because I'm dehydrated from a long run on Sat.   It always takes me two or three days to get back to the right level of hydration.

I've got to the point that I really only pay attention to my Tuesday weight as it seems the most consistent.