There was just recently a thread where this was discussed
http://www.3fatchicks.com/forum/meta...ual-cycle.html
Long story short, extrememly low carb/low cal diets (MRC) can wreak havoc on your menstrual cycle (for SOME). Back last summer after i was on MRC for about 2 months i started getting early, frequent, light periods (like every 2 or 3 weeks) and then they just stopped altogether. Ive been off MRC since last October, and i still havent seen my period again. Its been since last July