PMT Sufferers | Back to Vulnerable Groups List
It is a complex matter, and varies from woman to woman and over time. But a simplistic explanation is that the reason the fluid retention occurs is that in that part of the cycle - 'that time of the month', as popular parlance has it! - the changes in hormone levels cause the muscles in the walls of the blood vessels to relax. They can then easily be distended if salty food is eaten, because salt enters the bloodstream and takes water with it. So there is a greater volume of blood during this time, and it is this extra blood volume that accounts for the weight gain. The hormone levels are different again when the period starts, and these changed levels of hormone allow the blood vessel walls to tighten up again and squeeze out the extra salt and water from the blood stream. The kidneys then excrete the extra salt and water and the weight that was gained is lost again.
Avoiding all the recurring bodily changes by the dietary measures I have recommended would obviously be good for the physical and emotional health of women who currently experience PMT.
Note
I have modified my original belief that the excess fluid is all in the blood vessels. I now believe that most is in the blood vessels, while some may be in the abdominal cavity (ascites), and a small amount may be in the body tissues.
If you're unsure about which foods contain a lot of salt/sodium then click on the 'Sodium in Foods' link in the list of links on the left of each page.