Menstruation menarche has changed little in the United States since the 1950s. Menstruation is the most visible phase of the menstrual cycle and its beginning is used as the marker between cycles. The first day of menstrual bleeding is the date used for the last menstrual period (LMP). The typical length of time between the first day of one period and the first day of the next is 21 to 45 days in young women, and 21 to 31 days in adults (an average of 28 days). Perimenopause is when fertility in a female declines, and menstruation occurs less regularly in
Menstrual cycle of food types has been found between PMS sufferers and non-sufferers. The different levels of ovarian hormones at different stages of the cycle have been used to explain eating behaviour changes. Progesterone has been shown to promote fat storage, causing a higher intake of fatty foods during the luteal phase when progesterone levels are higher. Additionally, with a high estrogen level dopamine is ineffective in converting to noradrenaline, a hormone which promotes eating, therefore decreasing appetite. In humans, the level of these ovarian hormones during the menstrual cycle have been found to influence binge eating. It is theorized that the