Avoiding the Pitfalls of Fasting

Dr. Aaron Hartman

August 16, 2022


When I talk with my patients about fasting, they often tell me about the unpleasant side effects that they experience. Today I’d like to talk about some of the obstacles to fasting you might face and some ways to support your body for a more pleasant fasting experience.

The Pitfalls of Fasting

Some common uncomfortable effects of fasting include:

  • Low sugar episodes
  • Dizziness
  • Lightheadedness
  • Irritability
  • Hunger pains
  • Strong cravings for carbohydrates

These are signs and signals of metabolic dysfunction.


A healthy metabolism will burn through the calories of a recent meal and, within two to four hours, will have processed most of the food. In about six hours, it will be through the small bowel. By about eight hours, you would start using the energy stored up in your muscles in the form of glycogen. And at about 12 hours you would start tapping into your fat stores to remove fat and use that for energy.
What this means is if you only fast for about eight to ten hours a day, which is common for Americans, you don’t tap into fat stores, and you won’t lose weight. To lose weight, you have to go at least go 12 hours without eating.
If you have a lot of the above symptoms, it’s a signal that your body’s metabolism can’t switch from a sugar-based metabolism to a glycogen-based metabolism, and then to a fat-based metabolism. Your metabolism is inflexible, which in itself is concerning and a marker for metabolic disease, increased risk for autoimmune issues, inflammation, and the like.
So one way to tell if your metabolism is dysregulated is if you can’t fast for at least 12 hours without experiencing the symptoms above.

How Can You Avoid these Pitfalls?

The first key is to stay well-hydrated. When you do any kind of fast, you need more fluids and electrolytes. Drinking more clean, purified water by itself helps to suppress your appetite and flush out cell debris and metabolites. Your metabolisms can actually speed up through fasting and start to use different sources of energy, so you need more minerals and more water.
One way to stay hydrated while also including a good mineral source is to use a sparkling water like San Pellegrino that has lots of trace minerals and is also slightly alkaline. This will support your body in detoxifying while also maintaining your electrolyte fluid status.
When fasting 16 hours or more it’s a good idea to add in the trace minerals potassium and magnesium, because your body will flush these out as it’s flushing out toxins.
One reason many people have these fasting symptoms is that they have nutrient deficiencies of B vitamins, magnesium, or potassium. Since 60% of Americans are magnesium-deficient, 40 to 60% of us are potassium deficient, and 40 to 80% of us have some kind of B vitamin deficiency, the metabolism-reving effects of fasting can cause unpleasant symptoms. Addressing these deficiencies before and during your fast can improve your experience.
Gut dysbiosis can also cause unpleasant fasting side-effects. If there is a bacterial overgrowth in yeast, those bacteria create pseudo-neurotransmitters or chemicals that act like neurotransmitters and can drive hunger. Have you ever heard the term being “hangry”? That’s actually a state of mood instability induced by the bacteria in your gut creating these neurotransmitters. It’s not usually caused simply by a drop in blood sugar. Addressing gut health is another way to improve your ability to achieve an easier fast.
To summarize, using trace mineral support with magnesium, potassium, and B vitamins, drinking lots of clean water, and addressing gut dysbiosis, can go a long way toward a more smooth and pleasant fasting experience.

Next Time

In part four, I’d like to talk about the fasting mimicking diet and how it can be a bridge for many people to enter the fasting world.
If you feel like this information has been helpful, please leave us a comment on Facebook or Instagram to let us know. We’d love to hear from you on social media!
Since 2010, Richmond Integrative and Functional Medicine has been helping people to restore their health and hope with an integrative approach to conventional and alternative medicine that’s entirely science-backed. We at RIFM believe everyone is made for health. We offer a comprehensive, in-person patient membership program to ensure you get access to the care you need to thrive. 


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