When looking at the success of any diet plan for weight loss, the results are clear: it doesn’t always matter which diet you pick, it’s the one you stick to that produces long term results. The challenges with sticking to a diet are complex, but research is pointing towards even more difficulty in maintaining a weight loss program (or prescribed diet for other health conditions) in women who suffer from PMS.

PMS sufferers experience both physical and behavioural changes timed with their menstrual cycle, and often report symptoms of water retention, food cravings and weight gain. These symptoms are most notable in the fourth week of the cycle (late luteal phase/week before your period) and can leave a woman feeling as though her entire month of work on her diet is undone.

Women with and without PMS have been studied in various capacities to show that women with PMS increase their food intake in week 3 and 4 of their cycle(1–3), by increasing both carbohydrates (simple sugars notably) and fat while at the same time decreasing their protein intake. Although there is a small increase in basal metabolic rate in the luteal phase (thanks to hormone changes), it’s not enough to counter the increase in calories that most women consume during the same time period.

Women who are working on their diet may initially do best by honouring the hormonal changes in their cycle by increasing fruits in the luteal phase (to mimic the craving for simple sugars) and to allow a small serving of dark chocolate per day. Dark chocolate has been found to be an “irreplaceable” food craved by most women (meaning we can’t swap in anything to mimic the psychological effect when we eat it)(2).

The increase in eaten calories can also be linked to the mood related changes women experience with PMS. PMS suffering women crave more carbs and fats, and interestingly, these meals actually decrease their anger, irritability and depression during their premenstrual week (where the same foods given earlier in the cycle have no effect on their mood)(3). So perhaps women are craving these meals not only because of hormone driven changes in metabolism, but also as a psychological support for their hormone related mood changes.

So now what?

Some evidence suggests that we may want to time diet changes with these inherent monthly obstacles (start your diet during your period) so that women feel more successful and have better coping by the time they reach their PMS week. For us, we use this research to further emphasize the importance of treating hormones. If the PMS didn’t exist, neither would the cravings. (It may be hard to believe but women without PMS don’t actually have cravings!)

Women with lower progesterone levels have more difficulty with food and mood regulation around their cycle, and women with low estrogen have difficulty with appetite regulation all month long. Women with distorted progesterone have more depression and anxiety (and resort to rewarding themselves with food) and women with a higher perceived stress (cortisol) have more PMS. It’s a web that starts with a proper assessment, and better hormone balance.

The morale of the story is, if you’re trying to change your diet, be sure your hormones aren’t getting in your way. And if they are, we can help.


  1. Cross GB, Marley J, Miles H, Willson K. Changes in nutrient intake during the menstrual cycle of overweight women with premenstrual syndrome. Br J Nutr. 2001 Apr;85(4):475–82.
  2. Davidsen L, Vistisen B, Astrup A. Impact of the menstrual cycle on determinants of energy balance: a putative role in weight loss attempts. Int J Obes. 2007 Aug 7;31(12):1777–85.
  3. McNeil J, Doucet É. Possible factors for altered energy balance across the menstrual cycle: a closer look at the severity of PMS, reward driven behaviors and leptin variations. Eur J Obstet Gynecol. 2012;163(1):5–10.