How our menstrual cycle affects our blood sugars

Have you ever wondered why some days you feel like you’re just ‘on it’. You have all the energy, motivation and focus to achieve those daily tasks and you are smashing that weight training, run or pilates class, with what feels like very little effort?

Yet other days, you feel exhausted by 10am, struggle to focus and all you can think about is that chocolate bar that’s screaming out your name in the cupboard. If you’re a woman who is menstruating, then your hormones and blood sugars are likely to play a big role in why you’re feeling that way. Krista explains all…

If you are a woman who is menstruating with type 2 diabetes, Type 1 diabetes, or prediabetes, it’s vital to understand the impact your hormones can be having on your blood sugars, energy and cravings so you can work with your body and provide it with the fuel it needs when going through the monthly hormonal fluctuations. 


Every month, a menstruating woman goes through a cycle that prepares the body for pregnancy. Your cycle is regulated by four different hormones: 

  • Oestrogen, 
  • Progesterone,
  • Luteinizing hormone (LH) 
  • Follicle-stimulating hormone. (FSH) 


These hormones will fluctuate depending on where you are in your cycle and can have a significant impact on your blood sugars, particularly oestrogen and progesterone. 


Your cycle can be divided into 2 phases: the follicular phase and the luteal phase.

[Figure source]


The follicular phase 

The follicular phase starts on the first day of your period and if your period is the average 28 days, this phase will last for 14 days. It may last longer though if your cycle goes beyond that average 28 days. 


This phase includes menstruation where you have your period which involves the shedding of your uterine lining. This can last from 3-7 days. Some women do experience a peak in their blood sugars on day 1 of their period as oestrogen and progesterone levels are low during menstruation. 


The follicular phase also includes the maturation of ovarian follicles which prepares one of them to be released during ovulation. Whilst hormone levels are low during menstruation, they gradually begin to rise during the second half of the follicular phase.

The rise in oestrogen leads to insulin sensitivity which means blood sugars may naturally be lower. So how does this affect the way we feel? 


When we are more sensitive to insulin, this allows our cells to use sugar in the blood (glucose) more effectively, so we feel more energised. 


Oestrogen is also that power hormone that gives us confidence, motivation and focus so it’s a great time to start a new project, opt for a higher weight in the gym or have that awkward conversation you’ve been putting off for months! 

If you have a diagnosis of type 2 diabetes, or prediabetes, you may not experience that surge in energy because you have become insulin resistant, so your cells aren’t able to use glucose effectively. 


Ovulatory phase

This is where a mature egg is released from the ovary, and moves along the fallopian tube towards the uterus. Once the egg is released, it can survive for around 24 hours and if met with a sperm, you may get pregnant. 


Ovulation can cause a spike in blood sugars due to the rising levels of oestrogen, LH and FSH so you may experience more cravings and lower energy.


Luteal phase

After ovulation, you enter the luteal phase where the follicle that was released from the ovum (egg) collapses and the corpus luteum is created which releases progesterone and a small amount of oestrogen. This causes the lining of the uterus to thicken in preparation for pregnancy.


Progesterone makes the body cells more resistant to insulin action. This allows more sugar (glucose) to stay in the bloodstream, causing a rise in blood sugar levels. If you have a diagnosis of type 2 diabetes or type 1 diabetes and monitor your blood sugar levels, you may experience higher blood sugar levels during this time.


An increase in progesterone can also trigger cravings for carbohydrate-rich foods further contributing to poor glycaemic (blood sugar) control. 


Get to know your cycle

Tracking your cycle can be an empowering way to take control of your hormones and fuel it with the nutrients it needs depending on where you are in your cycle. 


It’s also an important consideration if you do have type 2 diabetes or type 1 diabetes so you can understand why you may be experiencing these peaks in blood sugars and know what you can do to help regulate them.


Consuming the right quantities of macronutrients including protein, healthy fats and complex carbohydrates is important to help balance your hormones but there are a few specific nutrients that you can focus more on at certain times of the month to help with cravings, mood, energy and of course blood sugars. 


Nourishing the follicular phase:

  • Iron-rich foods such as organic red meat, liver, legumes and pumpkin seeds help the body deal with the blood loss that occurs during menstruation which can help support low energy during this time.


  • Foods to help metabolise oestrogen as it begins to rise including probiotic foods such as kimchi, sauerkraut and miso and cruciferous vegetables such as kale, broccoli and cauliflower. 


  • Healthy fats to support an increase in energy levels during this time such as avocados, nuts, seeds and oily fish. 


Nourishing the luteal phase:

  • Complex carbohydrates – including sweet potatoes, beans and legumes to help keep you full without spiking blood sugars as much as refined carbohydrates which can help curb those cravings during this phase.



  • Omega 3 fatty acids – such as salmon, mackerel, chia seeds which may help reduce inflammation and help with bloating and cramping. 


The takeaway

Knowledge really is power when it comes to understanding your hormones and an important factor to consider when balancing blood sugars becomes a priority, particularly if you have type 2 diabetes, type 1 or prediabetes. (Although arguably they should always be a priority).


Knowing where you are in your cycle, means you can tailor your nutrients to support those hormonal fluctuations which may help towards minimising certain symptoms and improve energy, focus and mood.

If you want to get control of your cycle and hormone health as well as your blood sugars, why not speak to Krista about how you can.

Claim your free 20 minute call.