To be honest, I've never experienced this problem, but it may be that 150 grams of protein per day is a bit more than what you really need or your body can handle. Low carb is meant to be a high fat, adequate protein way of eating, not a high protein one, even though the low carb plans do state that higher amounts or protein (compared to the high carb/low fat/low protein diets) do not put any undue stress on healthy kidneys. Did they check to see if you had protein in your urine?