Hot flashes

I'm five days in on my pre-op diet and the hot flashes are killing me.  No one mentioned anything about it during my nutrition classes but an old friend mentioned the "carb flu" while she was pre-op.  

http://authoritynutrition.com/5-most-common-low-carb-mistakes/

I'm actually having trouble getting to my 1000 calories every day. Actually haven't hit it yet. I am down about 20 pounds.  The past two days I've been eating food. Yup, my surgeon allows eating!!  I've noticed I want to eat more frequently when I have actual food as opposed to the shakes. I can eat a half a head of lettuce with salt and vinegar, fill up, and not even make a dent in my caloric intake for the day. Eggs have also been super filling and tasty.  

Hot flashes seem to be normal according to blogs and posts online.  Amazing what carbs and the lack there of can do to you.  I suppose this is my detox!