I was reading More magazine the other night... yes, as an over-40 woman I am now reading an over-40 magazine... and in an article it was mentioned that the menstruation process burns about 500 calories per cycle. Hmm, says I, I have always been irregular... Eureka! This is why I am fat! Now, my regular-as-a-clock fertile-myrtle sisters who are holding on to extra pounds, I don't have an explanation for you. But I will keep looking!