Intermittent Fasting for Women
Updated: Jan 16
If you’ve been hearing about intermittent fasting (IF), experimenting with IF, or just wondering what IF benefits and pitfalls are, then let's dive in. Many men and women are intrigued and want to learn more about IF because they hear about it's many health benefits. However, there are some pitfalls that especially women need to be aware of. Nowadays, more research studies are being conducted in this area, but still more awareness is needed especially regarding women's health and IF's effects.
Intermittent fasting (IF) is a form of time-restricted eating, and considered a form of bio-hacking. There are many benefits to IF. Numerous studies, mostly done in men, have shown that IF helps balance blood sugar, burns fat, resets gut microbiome, improves cognitive function, lowers risk of various diseases such as diabetes and cancer, reduces inflammation and improves new cell growth.
There are different types of intermittent fasting, they are:
Time Restricted Eating - Eating Window from 8am - 6pm, typical fast 12hrs
One-meal-a-day (OMAD) - Eating only a single meal, typical fast 24hrs
Alternate-day Fasting - Eating every other day, typical fast 36hrs
The 5:2 diet - Eating for 5 days as per normal, fasting for 2 days, typical fast 60hrs
Water fast - Drinking water only, fasting for 3 days, typically 72hrs
Dry Fast - No food and drinks, typically supervised in a medical facility
There are 5 stages to intermittent fasting, they are:
At 12 hours, you're in ketosis which is when the body starts to break down and burn fat
At 18 hours, you’re fat-burning and generating ketones
At 24 hours, you're in autophagy stage. Your cells are increasingly recycling damaged and old cells, while also breaking down misfolded proteins linked to Alzheimer’s and other diseases.
At 48 hours, you're producing 5x as high of your growth hormone as when you started your fast.
At 54 hours, you're becoming more insulin-sensitive.
At 72 hours, you're breaking down old immune cells and generating new ones.
Needless to say, these studies were done in males. Good news is that more studies are being done in both men and women today. A more recent study that was conducted in both men and women, concluded that "time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day." This study highlights that skipping breakfast may not be the most efficient approach if weight loss is your goal. First meal of the day, breakfast, allows us to break-a-fast and it supports women's hormones in critical ways. A 2005 study found that IF was supportive for men, but it impaired blood sugar for women. A 2013 study in rats found that females experienced a reduction in the size of their ovaries, stopped ovulating, and had sleep problems. Therefore, IF may not be ideal for women in their reproductive years. IF can put stress on the body that negatively impacts hormone balance. Hormone imbalances can lead to a cascade of unwanted symptoms, issues with your period, and even infertility. Fasting could also negatively impact your energy, mood and libido if taken too far.
So then, should women practice Intermittent Fasting? Female biochemistry is cyclical in nature, which means that we need to eat in a cyclical pattern and in alignment with our cycle phases. Men and women both have a 24hr circadian rhythm, but in addition to this women also have a 28 day infradian rhythm. Think of it as seasons Follicular (Spring), Ovulatory (Summer), Luteal (Fall) and Menstrual (Winter) phases. When it's cold outside, you're likely craving warm foods; similar to when it's hot outside you're likely craving cooling foods. For example, during Ovulatory phase woman's body temperature rises, and therefore we may crave more cooling foods. A study conducted solely in women showed that the hormones responsible for moderating the follicular and luteal phase, can be interrupted by weight loss related factors, causing changes in reproductive functions including anovulation and infertility. In simple terms, women's body isn’t the same every day and neither should be their diet! Because of constant fluctuation of hormones, intermittent fasting may not be suitable for women at every stage of the reproductive cycle. Additionally, anyone with a history of disordered eating, intermittent fasting may not be appropriate due to its restrictive nature.
If you chose to experiment with IF, the best time to fast if you're in your reproductive years, is during the Spring season or Follicular phase. Women with PCOS, that chose to experiment with IF may actually improve fertility due to the increased insulin sensitivity. Women in menopause, can also experience benefits of IF, since hormones decline, leading to slower metabolism and insulin resistance, both of which IF can help with. Whichever you chose, make sure to align with what is the most nourishing for your body and mind, depending on your individual cycle phase or stage of life.
For more information on Intermittent Fasting and how to determine what works best for your biological clock, book an Introductory Session.