For anyone who isn't familiar with the term ‘intermittent fasting’ it describes a practice of going without eating or snacking for determined period of time. This amount of time can differ depending on the style of intermittent fasting you are doing - some people choose to go hours without eating, and some go days.

Popular styles of intermittent fasting

• The 16/8 Method: Fast for 16 hours each day, for example by only eating between noon and 8pm.
• Eat-Stop-Eat: Once or twice a week, don’t eat anything from dinner one day, until dinner the next day (a 24 hour fast).
• The 5:2 Diet: During 2 days of the week, restrict calories to 25% of your usual intake.

The current understanding behind this style of fasting is that it allows for our insulin levels (the hormone that controls our blood sugar levels) to go down, which prompts our body to begin to use fat as energy.  There is some research that supports the use of intermittent fasting as a tool to support weight loss, blood sugar balance, and inflammatory health conditions. The issue with this research is that a lot of it has been done of animals, and very few studies have been conducted on humans – those that are human studies are small in scale and fail to explore the long-term health risks or benefits of fasting.

Results of small-scale human trials comparing the benefits of fasting within males and females show that fasting improved blood sugar control in males but not in females, and triggers a bigger stress response in women compared to men.

There are a number of health risks associated with this ‘style’ of eating, and it is known that intermittent fasting is not safe for individuals that have a pre-existing medical condition, are underweight, have a current or past eating disorder, or are pregnant or lactating. Below we take you through some of our main concerns around this popular trend within the wellness industry, and how it impacts our delicate hormones.

THE MAIN CONCERNS 

Female Hormones

Hormones are sensitive. The hormones that regulate key functions throughout our body such as ovulation, metabolism, and our moods are extremely receptive to our energy intake. It all starts within an area of our brain called the hypothalamus, which controls the release of a key hormone called gonadotropin releasing hormone (GnRH). This hormone essentially communicates to another area of our brain called the pituitary gland to release luteinising hormone & follicle stimulating hormone. These two hormones communicate with our ovaries to release oestrogen and progesterone at certain times throughout our cycle to stimulate ovulation or support fertility.

Research has shown that even short-term fasting or ‘skipping a meal’ can alter the communication pathway between our brain and ovaries, prompt hormonal imbalance, and put our hormonal system on alert.

Stress response & energy balance

The female hormones that control our monthly menstrual cycle are so responsive to the changes that occur in our physical body. The way intermittent fasting stimulates weight loss can trigger a stress response in our body if we are also experiencing stress from other areas in our lives. This includes mental stress from overworking, physical stress from over exercising, or even emotional stress from trauma.

It all comes down to our energy balance, which is essentially the balance between what we are putting in our bodies, and what energy our bodies are expending throughout the day. When we are in a negative energy balance for a long time our body enters a stress response. This triggers our reproductive system to shut down ovulation, as the body prioritises survival over supporting a pregnancy. This is when we will see women experiencing irregular menstrual cycles, anovulation, or amenorrhea (loss of their menstrual cycle).

Obviously for women who are wanting to conceive this is an issue. But what a lot of women don’t understand is that even if you aren’t wanting a baby, ovulation and a healthy menstrual cycle is essential for health. The hormones secreted during our menstrual cycle influence all aspects of our being, and play balancing and protective roles in our mental, digestive, metabolic, immune, cardiovascular, and bone health.

This stress response and high cortisol can also make it a lot harder for us to lose weight. So, if you are considering doing intermittent fasting for this reason, reconsider your reasons behind it, and consult with a health professional.

Disordered eating habits

One of the biggest issues we have with any style of diet, and particularly with intermittent fasting is that it promotes disordered eating. For most females it is hard to get through your younger years without experiencing some sort of body image issue. We are at the mercy of a society that places importance on our looks and uplifts abnormal beauty standards. For any women with a history of disordered eating, intermittent fasting is extremely dangerous as it encourages restriction, and nullifies intuitive eating. Restrictive eating creates a stress response in our body, which as we have already spoken about, impacts on our highly sensitive hormones.

Restrictive eating can also be the pre-cursor to binge eating habits, which can create a cycle of self-loathing, and further damage our relationship with food. With all of the information available to us through the internet and social media producing ‘experts’ through a click of a button, food and eating has become complicated and confusing.The relationship we have with food is one we need to nurture in order to achieve health and wellbeing. Tune into your bodies unique energy needs, and nourish it with whole food when it asks.