This post may contain affiliate links which won’t change your price but will share some commission.
One common question that comes up related to fasting is the question of hypoglycemia or low blood sugar. Many folks are worried that they will have low blood sugar and not be able to get through a fasting time. This is a danger for some people, but not as many as you might think.
I want to add a disclaimer right here at the beginning of this discussion . If you take meds to lower your blood sugar, including oral agents or insulin, fast can very easily lead to hypoglycemia. Anyone who wants to fast under these circumstances, needs to work out a plan with your doctor to head off any hypoglycemic episodes as these can be very dangerous. For all the rest of you, let’s go on to see how you can fast and what it might to do your blood sugar levels.
Symptoms of hypoglycemia
The symptoms of hypoglycemia include confusion, sweating and tremor. They can also include a feeling of hunger, shakiness and weakness. Again if you are medicine to lower your blood sugar and have these kinds of symptoms, check your blood sugar right away and take some protein and a carb to raise your sugar right away. This could include cheese, crackers, fruit, nuts, etc.
But does fasting cause low blood sugar for the rest of us?
This is not likely for the average person because blood sugar is tightly monitored by the body. When you fast, the body first uses the blood sugar circulating in the blood stream and then moves on to the sugar stored in the liver as glycogen. This breaks down into usable sugar quite easily. After 18 to 24 hours this supply becomes depleted and the liver begins to make glucose out of the fat in our bodies. Our brains are also able to adapt and use ketones, the byproduct of fat breakdown, for fuel rather than glucose. So most people who are fasting, especially less than 24 hours should not see a problem with low blood sugar.
What about the weakness, dizziness, and fatigue I feel with fasting?
Many people complain about these symptoms when they first start fasting. Many times this is part of the adjustment period and within a few days will resolve. But if not and to avoid that feeling, make sure you are getting enough electrolytes in your diet. Use sea salt on your food when eating or put a pinch in your water. Some folks sweat by pickle juice and that is really helps them feel much better. There are several options to meet the need. But if you are struggling this where I would encourage you to start so as to resolve these symptoms.
But I have hypoglycemia according to my doctor, so can I fast?
Proceed carefully. Start out with 12 hour fasts and work up as your body adjusts. You may find that you have no problem. If you don’t feel well see the paragraph above and see if adding some electrolyte sources to your diet makes a difference. Also don’t start out with any daily fasting. Some folks need plenty of time to adapt.
My other piece of advice is to make sure that you are eating enough fats and protein in the time you eat. Many folks who struggle with hunger and some of the dizziness and headaches are eating very high carb. The carbohydrates process very quickly in your body and leave you feeling hungry and sometimes with a temporary period of low blood sugar. To help avoid that you want plenty of good fats in your diet.
Leanne: I took Chromium Picolinate (a supplement that is indicated for balancing and lowering blood sugar) for years and always horrible low sugar, shaky and very weak. Once I cut out the chromium and started doing IF I don’t have those episodes anymore. I have been doing IF for a year come this May(2019).”
Chrystal: ” I started (fasting) in mid December. I try to stick as close to 18:6 as I can, but many days I might end up 17 or even 16 hours of fasting. I normally eat at 12pm, then 3pm snack and dinner by 6pm. I have consistently lost 1.5lbs a week. What keeps me going though is how great I feel. I have more mental clarity and all around feel better with more energy. I even notice my muscles are all feeling more defined. As a teenager, I was 105 lbs and ate whatever I wanted (ie sit down and eat an entire large pizza by myself and never gain a lb) Then I was diagnosed hypoglycemic. Was preached to and told how I needed to eat small meals all day every 2-3 hrs to keep blood sugar stable. They even had me drinking Ensure Plus b/c I didn’t want to actually eat. My mom was diabetic and always so frustrated by me b/c I was always in the 60’s when I would test with her. Looking back, I now realize that it was when I started working and forcing myself to eat breakfast (as I naturally ate around 10:30-11) is when the hypoglycemic episodes started. Then when following drs orders all these years (first real weight gain was 30 lbs my first semester of college after being diagnosed) and steadily gained all these years. Finally last year I was at my heaviest of 179 lbs. I am so thankful I finally found IF. I think it is a game changer. I also just a few days ago found this group (Intermittent Fasting for Women FB group) and I think having the support and help from others will continue to get me where I need to be. I’m currently reading Obesity Code by Jason Fung.
What is crazy is all of my hypoglycemic episodes have completely went away since doing IF. I never get that low blood sugar, feel like I am going to pass out, body actually shaking any more. I have even done two full day fasts (pushing it to 40-41 hours of fasting) with no ill effects. By that night I felt like I had even more energy and my Hubby thought I was crazy being in such a good mood bouncing off the walls, haha. ”