What No One Will Tell You About Fasting
Let’s take a look at HOW fasting works, especially in the female body. In theory, fasting sounds like a great way to see faster results. A common argument that I hear all the time is how our ancestors fasted all the time, whether it be from a need to go hunt and gather their food before eating it or from something like famine that limited the availability of food.
While I do believe we should be able to be flexible and go without food without experiencing major blood sugar symptoms (classic signs of hangry, shaky, irritable, headaches, faintness, etc.) this does not mean we should do this on a daily basis for months and years and expect our health not to suffer.
But why did it work for our ancestors?
When we look back at our ancestors we have to remember the roles that played out during that time. If food was scarce, the men went out and did the hunting (a fasted workout you might say…) whereas the women stayed at camp to tend to the children. We also have to remember the stressors that people were experiencing during this time as well. On a daily basis the main source of stress was the availability of food and possible danger from invaders (which wasn’t really a daily concern for most).
Today we are dealing with financial stress, lack of community, lack of sunlight, lack of sleep, too much blue light, the news (need I say more), insane exposure to toxins in our food, water, and environment, not to mention the fact that many women are trying to manage a household while also working full or part time. This list could literally go on for miles. So while I do draw inspiration from our ancestors on what they ate, I don’t just automatically think that everything they did can be cross-applied to us because the environment in which we live changes everything.
What about the studies?
They prove fasting is the secret to healing right?
It is not hard to find studies on the many benefits of fasting. I do not discredit these studies but again we have to look at how to apply these studies to us. The main problem with these studies are that they were performed on men and postmenopausal women. In other words, if you are currently having a menstrual cycle, are pregnant, or are breastfeeding you are excluded from these studies. Do you fall into this group? If yes, then fasting may not be all it has promised to be.
So how does fasting work?
First you need to know that every single cell in your entire body with the exception of your heart runs off of glucose. Carbs, Fats, and protein can be broken down into glucose to provide energy to your cells with the easiest form being from carbohydrates. The food we eat gets broken down into glucose which enters into the bloodstream and becomes blood sugar. This blood sugar is picked up by insulin and shuttled into the cells so that they can do what they need to do. If this blood sugar or glucose is running low, your body’s alarm system will go off alerting you that you need fuel. This often comes through as hunger but can also come through in more emergency situations like sugar cravings, irritability, brain fog, shakiness, etc (all those blood sugar symptoms I listed before…).
If we don’t respond to these symptoms - say we push through the hunger- you are technically entering this “fasted” state. When we fast, your body relies on a process called gluconeogenesis which will allow your body to produce glucose from stored energy.
Cortisol, aka your stress hormone, is released from the adrenals and is what stimulates this process. If your adrenals are already taxed from your stressful lifestyle then this right here is problem number one, it is adding MORE stress to your life.
The other issue to be aware of with fasting is that cortisol will trigger gluconeogenesis in BOTH muscle tissue and fat tissue. This means that your body will break down both your muscle and fat tissue to create energy. This is what can leave you struggling to see results - you work out, eat healthy, but still see no muscle definition or are struggling to lose those last 10-20 pounds.
Maintaining muscle is not just an aesthetic goal either. It is essential for a healthy metabolism and healthy aging as well. We don’t want to burn muscle as fuel if we don’t have to.
How Stress Levels Impact Hormones
Most people these days are already stressed out, not getting enough sleep, are eating nutrient deficient diets, sit most of their days, are getting too much blue light and not enough sunlight all of which are taxing on your adrenals. Fasting and fasted workouts only add to this stress.
High levels of cortisol will reduce the production of sex hormones. This is both a resource issue and a protection mechanism. Cortisol and sex hormones are made from cholesterol. If there is a high demand to produce cortisol, it will decrease the resources to make sex hormones. As a female, your body will also be more sensitive to high stress hormones. It senses that it may not be safe to reproduce because of this stress which reduces the production of hormones even further.
Have you ever had a stressful month and noticed that your period was delayed? Have you ever experienced Hypothalamic amenorrhea in which your cycle went missing for months? These are common signs of stress impacting female hormone regulation.
High cortisol also has a direct impact on slowing down thyroid function. This is usually a means to conserve energy, reducing how much fuel is required to do basic functions. This results in symptoms of weight loss resistance, fatigue, digestive issues, sleep issues, thinning hair and more.
Is there ever a time where fasting could be OK?
I do believe there is a time when fasting can be OK and not impact hormones BUT you have to get real with the stressors in your life. You need to be prioritizing 8-9+ hours of sleep, getting lots of sunlight particularly in the morning and evening, spending minimal time on electronic devices, avoiding and reducing toxic exposure, and overall managing stress really well. Having a robust nutritional status is also important as fasting can often leave you depleted.
Lastly, If you do fast, this does not mean that you get to eat whatever you want during your eating window. In fact, this means you need to be EVEN MORE intentional about what you eat because you are naturally going to be eating a bit less and therefore taking in less nutrients. So no, you still can’t live off of french fries and ice cream just because you are fasting.
When I go over this shift in mindset with clients they often decide that fasting is not a good fit for their lifestyle (not that we can really ever just eat french fries and ice cream but you get the picture).
What does it mean if fasting is the ONLY way I can lose weight?
This requires diving deeper into your health to find the WHY. There is always a why.
Oftentimes we see this coming from sluggish thyroid function, a cellular issue in which your cells cannot use thyroid hormone efficiently, or insulin resistance. There could also be imbalances in the gut microbiome that are driving inflammation and poor detoxification which can slow the metabolism.
These all require addressing underlying mineral imbalance, nutrient deficiencies, blood sugar imbalances, and digestive concerns to see results. This is not a quick fix but is a lasting fix. Using functional testing like the HTMA test, bloodwork, or the GI map can help you navigate your healing journey and get you the answers that you have been looking for.
When you really COMMIT to diving deep into your health and healing your body from the inside out, you will find that you are able to find a sustainable lifestyle that keeps you healthy.
BOTTOM LINE?
The bottom line is, if you are a female who is cycling, pregnant, or breastfeeding, fasting and fasted workouts are not a sustainable approach to supporting a healthy metabolism. There are so many other ways to improve your metabolic function and see lasting results. While you may feel good fasting right now, it is going to catch up with you sooner or later (speaking from experience here!) so you might as well get started on supporting your health foundationally now rather than later!