Concerned...vets, please chime in

I had surgery on 8/7/12. I have lost 55lbs since then (+12lbs lost pre-op). I have gone from Sz 22 to a comfortable size 16 and feel great about my progress. I stay below 800cals and 40 carbs daily. I take a SL B-Complex as well as Opurity bariatric multi daily (although I admit to forgetting on occasion). I get in 80+ grams of protein almost without fail. I usually have to do a couple of shakes per day to accomplish this. The main thing I have had issues with is fluids. I am doing better but still probably only get in the minimum 64oz many days, some days less. I have resumed drinking coffee, usually 12-16oz per day. My research indicates that this should not be enough to cause any diuretic effect.

My problem is with muscle soreness. At first, it seemed almost more like joint pain in my hips and I attributed it to reconfiguration of weight, etc. NOW, my thigh muscles and even somewhat my back feel like I've been running bleachers or something (I have not been to the gym or performed any exercise out of the normal walking at work). They are SORE. I am concerned that my body might be feeding on muscle or something....?? I had labs drawn a little over a month ago and they were fine. However, my levels of vitamins were not tested, just basic kidney function, liver, etc. My weight loss has also slowed significantly (maybe losing 2lbs per week for the past 2-3 weeks) but I do not know that these issues are related. Thoughts, advice please?

Slowed weight loss is probably not related.  It does slow down over time.

Call your doc and have your labs pulled - all of them.  What you're feeling could be anemia, low B-12, low potassium, among other things.  The coffee shouldn't be causing this either.  What you may want to try - just because it won't hurt anything - is drinking Powerade Zero (or some other no-calorie sports drink) just to make sure it's not an electrolyte problem.

Have they tested for your thyroid--it is a simple blood test.  A low thyroid can cause muscle soreness, weight gain, etc.  I know before I was diagnosed--I felt like I had the worst case of the flu.  I would avoid drinking things at hockey games as it hurt so much to have to walk up the stairs to get to the bathrooms.  Just a thought.

I have been on thyroid medication since the age of 11. It is tested regularly. Thanks for the try

Are you on any cholesterol med? Statins can have muscle soreness/pain as a side effect... just another shot in the dark!!

Go see your doctor. What you're experiencing is not normal and needs to be checked into by your doctor.