While working as a nurse with Dr. Robert Atkins, I adopted a low carb diet. My goal was to avoid my genetic tendency for developing obesity and type 2 diabetes.
I had the tools at hand to monitor urinary and breath ketones frequently. After months I noticed that a few days before my period, ketones would drop or even disappear. This coincided with mild PMS symptoms including weight gain and the re-emergence of hunger and cravings. Ketones would return by the 2nd day or so of my menses.
I began to mention this to my patients who wanted to monitor urinary ketones. I didn’t want them getting discouraged if they experienced the same. Many would return and tell me they noticed the drop in ketones as well. They appreciated having advanced warning.
We also observed that with low-carb regimen, PMS symptoms over time would decrease, sometimes to the point that a woman would be surprised when she began her flow. At the start of the plan others would mention that the first period would in some way be worse before getting better. To my knowledge this has not been studied.
What I learned is that any hormone changes in women can increase insulin resistance, which makes the body produce more insulin to get the same insulin benefit. At puberty and menarche when girls need to gain body fat they become more insulin resistant. I have been a carb addict but my cravings increased significantly at this time as did my weight.
Hormones also fluctuate during the menstrual cycle. During pregnancy, peri-menopause, and menopause there are significant hormone changes accompanied by increased insulin resistance.
This change of life stage (peri-menopause) for me was difficult. I lost ketones but still gained weight on my maintenance plan (my strategy was to adopt a 20 gram carbohydrate level and stay there to minimize weight gain). I believe that this is one reason why women can have such difficulty during peri-menopause and menopause managing weight even when doing everything right. I also believe these hormone fluctuations can cause more havoc if one is genetically prone to diabetes. This is all the more reason to adopt a low carb lifestyle now, to decrease carbohydrate intolerance during those normal hormonal life changes.