I have been exercising and eating healthily. I am desperately trying to lose weight before my sister’s wedding in July. I have been doing this for several months now, but my weight really fluctuates during the month. This morning, despite eating so little the week before, the weighing scale shows I have gained almost 1kg! Does this have anything to do with my menstrual cycle?

Yes, it does. For a woman who is still menstruating, your weight can fluctuate quite drastically during certain days of the month.

Weight gain usually occurs five days before your period. I know the feeling. You have been exercising and eating salads and practically starving yourself. You are feeling quite pleased with your weight loss progress.

All of a sudden, you weigh yourself one morning, and wham!, the weight scale shows your weight goes up instead of being on a downward trajectory.

You are frustrated and you don’t understand why. It worries you quite badly. You make a mental note to exercise even more in the evening, and you will skip dinner completely.

But if this weight gain happens around five days before your period, it is quite normal. You will be back to normal after your period, or even during your period.

Why does this happen?

It is because of the hormone progesterone. You have two female reproductive hormones, oestrogen and progesterone. If you take the first day of your menstrual cycle as Day 1, then oestrogen dominates the first half of your cycle, which is about two weeks for most women, and progesterone dominates the second half.

Progesterone is responsible for water retention, and hence your weight gain is actually due to water retention.

How does this happen?

It is because your menstrual cycle and reproductive hormones, especially progesterone, are meant to prepare your womb and body for possible pregnancy.

If you don’t get pregnant, then progesterone levels fall the moment you get your period. Water retention then falls as well, and you “lose weight”.

You may find yourself going to pee in the toilet quite often when this water retention goes away.

How many pounds can I expect to gain around this period? (I hate this!)

I know. I hate it, too. Pre-menstruation water retention can gain you anything up to 4kg.

Most women gain around 2 kg. I know, that’s a lot of weight gain.

This is because each cell in the body retains a very tiny extra drop of water.

Is water retention the only reason for my weight gain around my period?

It is the main reason, but not the ONLY reason. When you have premenstrual syndrome (PMS), you tend to eat more than usual, especially comfort food like chocolate or cakes. You crave sweet things and junk food, you eat, and then you feel really bad about it.

Your body is actually designed to crave such things to prepare for the pregnancy that might be coming. When the pregnancy does not happen, you are left with weight gain from all that excess (and unhealthy) eating.

If you eat healthily and exercise normally, there should be no post-period weight gain from actual calories, and your weight should return to normal after your period.

My sister does not gain weight just before her period. She gains weight two weeks before her period instead. Is this cause for alarm?

Being alarmed when you gain weight is very subjective and different from being alarmed because you have symptoms of a disease.

Some women gain weight during ovulation, which happens in the middle of your menstrual cycle. In other women, weight gain happens after ovulation, and peaks at the first day of their period.

For yet other women, weight gain happens during ovulation, falls off, then starts to climb up again leading up to the period.

It’s different with every woman.

Once again, weight gain during ovulation is mostly due to water retention. But beware not to overeat or give in to your cravings, because weight gain can easily come from consumption of excess calories that we spoke about.

How do I avoid being freaked out by all that weight gain?

First of all, understand that it is part of your menstrual cycle and know your own pattern. Keep a daily weight chart and compare it month on month.

Really, really watch what you eat, and exercise normally. Remember, you lose more weight by watching what you eat and eating healthily than by exercising.

Drink plenty of water to keep your body from retaining water (I know, it’s a paradox). Sleep as much as you need, avoid alcohol, and avoid sweet food and refined carbohydrates.


Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, e-mail starhealth@thestar.com.my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.