Why may these diets cause issues with women?
As women we function off a 28 day cycle. (or so) once we are of child bearing age. When hormones are regular they will increase during the first part to prep our body for concieving, then in the second half if we do not conceive they will start to drop.
Along with our cycle our metabolism also increases and decreases throughout the month. During our first half, we have a slower metabolism as our hormones are on the rise, we have less of an appetite from this as well. In the second half our metabolism speeds up and we have/want to eat more complex carbs, etc to support this. We are also more at risk for blood sugar dysregulation during this time.
You can see just from those facts that sticking to one way of restrictive eating could potentially harm you at certain times of the month. If you have imbalanced hormones and already have been diagnosed with something like estrogen dominance, pcos, or diabetes, then restriction and causing any other sort of additional stress on our body will only make things worse.