Hi aloevera
I used to get this but it was towards the end of the cycle ie the last week - this is when the hormones are at rock bottom - oestrogen is at its peak during the middle two weeks! I think blood sugar metabolism is linked to progesterone but I haven't looked into why this is. During the week before my period, I used to go from hungry to shaky, sweaty, low blood sugar in a very short space of time. So bad that I even went to the doc about it! I didn't know anything about perimenopause at the time but it was definitely happening more extremely in my 40's which was way before menopause for me. I used to carry glucose tablets around with me (not ideal!).
Best thing is to make sure you keep your blood sugar levels up by eating little and often and low GI foods (slow release carbs especially) eg whole grains, apples, protein etc. Have a good breakfast - oats, muesli, fruit etc. You will know your hungry time - mine is in the morning.
Hurdity x