I have definitely noticed that when starting back on low carb a couple of weeks ago, the hot flashes returned almost immediately. Previously they had slowly tapered off over a year or so and were virtually gone. Then gave up the carbs and they came rushing back pretty strongly. After a couple of weeks on this WOE, they are lessening slowly. I think it must really be true that estrogen is stored in fat cells and when you begin to lose weight, the cells shrink and estrogen is expelled back into the bloodstream, causing hot flashes. So, I welcome them now because they seem to be an indicator that the weight is coming off.