Skip to main content

Intermittent Fasting FAIL? You're Not Alone!

Several years ago, I tried intermittent fasting when it first became all the rage. Result? I was hungry all day and ended up binge eating that night. I'd been on a low-carb diet for quite a while.

I now know that the problem was likely low cortisol. I've had symptoms of low cortisol all my life: allergies, wonky blood sugar, sinus infections, and recently, my three-month bout with bronchitis--in the summer. And I'm hypothyroid, a condition that tends to go hand-in-hand with low cortisol.

Cortisol helps regulate blood sugar. Without enough cortisol you can get hypoglycemia; your liver won't make enough blood sugar. In other words, I need to eat breakfast, lunch and dinner. When I had a more stressful job, I also needed some snacks in between.

Since about half of people with thyroid problems also have adrenal problems(1), and Syncrap (levothyroxine, a thyroid medication) is the second-most prescribed medication in the US(2), low cortisol must be a pretty common condition. Yet I rarely read about any caveats with regard to intermittent fasting. When Chris Kresser published an article saying he didn't recommend fasting for his patients with wonky blood sugar (that is, most of his patients), some Jason Fung fanboys chimed in with suggestions to drink enough water, eat enough fat, and of course exercise. Water and fat are necessary nutrients, but they don't fix endocrine problems. Further, drinking water without any salt can make you feel worse if you have low cortisol. (In fairness to Fung, he wrote that people with too much cortisol shouldn't fast, but doesn't say anything about low cortisol.) Kresser writes that fasting raises cortisol levels (and therefore blood sugar), but for someone who doesn't make enough cortisol, it seems to me that fasting would cause hypoglycemia.

Obviously, intermittent fasting isn't on my to-do list for 2020. I'll eat breakfast, lunch and dinner with plenty of fat and salt and few carbohydrates. I'll take my adrenal and thyroid medicine and my supplements. Nassim Taleb defines rationality as what leads to survival, which often means ignoring some of the experts.


  1. Stop the Thyroid Madness Updated Revised Edition by Janie Bowthorpe, page 47. Laughing Grape Publishing, 2019.
  2. Prescriber Checkup By Ryann Grochowski Jones, Lena V. Groeger, Charles Ornstein, ProPublica, Updated February 2019. Accessed January 1, 2020. https://projects.propublica.org/checkup/

Comments

Galina L. said…
Regularly as a FB group admin I come across interesting cases. Sometimes some people develop sleep problems, increased irritation, even high blood pressure while eating less often. When somebody complains on such set of problems I always ask how often the individual eats/or advice right away to eat an extra meal a day. So far everyone got better. I do come across benefits of fasting very often, however, humans do have individual differences
jeangenie said…
Thank you for this post. It describes me in a lot of ways. Sinus infections and hypoglycaemia - in the middle of the night I can be so hungry that I have to eat to get back to sleep. I don't know about thyroid. I've never had occasion to have it checked but I know I have trouble when I try intermeittent fasting. I can manage to push breakfast back to lunchtime but then I eat something before bed or in the night. I'll follow your links and investigate further. Jean x
Lori Miller said…
Good to hear from you, Galina! I agree people need an individualized plan.

Jeangenie, I'd recommend a 24-hour saliva cortisol test.
Val said…
Belated holiday greetings Lori! (Damn, this holiday season seemed to come & go even FASTER than in years past!)
My latest numbers from my DIY thyroid tests were improved and I am feeling a little better (generic levo & Thyro-Gold) although still plagued by fatigue & cold intolerance...
I just have to wait it out for the rest of our (relatively mild) Texas winter - but 32 degrees this AM made me anxious to finish up in the barn & return to my toasty lil’ farmhouse!
Lori Miller said…
Dr. Davis says free T3 and free T4 should be in the upper half of the reference range. He also recommends taking 500 to 1000 micrograms of iodine per day in the form of kelp tablets.

I think my cold tolerance is a lot better, but it could be the mild winter we're having.

Popular posts from this blog

Dana Carpender's Podcast; Dr. Davis on YouTube; Labor Day Sales

Dana Carpender, who's written several recipe books and other works on low-carb, has a podcast and is still writing articles at carbsmart.com. She's a terrific writer and amateur researcher (otherwise known as reading , as Jimmy Dore jokes ). I use her book 500 Low-Carb Recipes all the time and I'm looking forward to hearing more from her. I've embedded her podcast on my blog (click on the three lines at the top right if you don't see it, or go to Spotify or other podcast source if you're getting this by email). Carbsmart.com doesn't seem to have a blog feed, so if you want to see the latest posts there, you can sign up for notifications at their site. Dr. Davis has been putting a lot more videos on YouTube, so I've added his channel to the lineup. Click on the three lines on my blog if you don't see it, or go to his channel here .  * * * * * Primal Kitchen is having a Labor Day sale-- 20% off everything. They sell high quality collagen powder, con...

Fasting blood sugar & insulin have crept up!

It's pretty bad when even conventional medicine thinks your blood sugar is high. I had lab tests done last week, as I do every year, and saw things were going in the wrong direction. Photo from Pixabay . Uh-oh.  Ideal blood sugar is about 70-90. Your blood sugar can be high because you're stressed or ill, but I felt OK. I can't blame it on cortisol, which was smack in the middle of the normal range. And my A1c, which reflects blood sugar over the past few months, shows that whatever is going on has been happening for a while. My insulin is more than double what it should be. Oddly, my triglycerides, which typically indicate carb consumption, were good.  I don't have an explanation for the triglycerides. I should have suspected something was wrong, though. I've felt very tired and a little sad for the past few months. Unlike many people with higher than ideal blood sugar and insulin, I had only gained about three pounds.  Regardless of my good weight and triglyceride...

Interview: The Microbiome's Effect on Almost Everything

Mark L. Cannon, DDS, MS joins Bret Weinstein of the Darkhorse Podcast for a discussion about the oral microbiome and its downstream effects on everything from acne to Alzheimer’s. Dr. Cannon is a pediatric dentist and professor of otolaryngology (ear, nose and throat medicine). It's an hour and 44 minutes, but well worth your time. Link here: https://www.youtube.com/watch?v=fjkOgCXiMeE

YouTube invites creators back; says Biden pushed censorship on COVID and politics

Google, which owns YouTube, is inviting back creators it kicked off the platform for content about politics, elections, and COVID. Google says the Biden administration pressured them to censor this content, and now Europe is trying to force them to censor lawful content. Jim Jordan, Representative from Ohio, explains on X. Thread here .  Created with AI on ImageFX.  YouTube creators banned or suspended for COVID content (source: Grok). Click to enlarge. Rep. Jim Jordan @Jim_Jordan 2h • 15 tweets • 6 min read • Read on X 🚨BREAKING: Due to our oversight efforts, GOOGLE commits to offer ALL creators previously kicked off YouTube due to political speech violations to return to the platform. BUT THAT’S NOT ALL. Thread: YouTube also: -Admits the Biden Admin censorship pressure was “unacceptable and wrong” -Confirms that the Biden Admin wanted Americans censored for speech that did not violate YouTube’s policies -Details when YouTube began rolling back its censorship policies on p...

Infrared Light: How much is too much?

It's the sort of thing that sounds like quackery: a pad with tiny red LED lights and a few buttons that's supposed to help you heal, just $30 on ebay. I never would have bought it, but Dr. Davis gave a presentation on infrared light late in 2024. Since I was still suffering from achilles tendonitis after being floxxed , I decided to try it.  I wrapped it around my ankle and turned it on the lowest setting for five minutes. Nothing seemed to happen, but the next day, I wrote,  My tendonitis is GONE after one 5-minute treatment! I didn’t feel it doing anything, I didn’t think it was going to do anything (at least not that quickly), but for the first time in several months, I’ve gotten out of bed and started walking normally and didn’t have any pain reaching with my left arm. I'd been shuffling around like an 80-year-old woman after getting out of bed in the morning. The tendonitis returned, but it was improved. I eventually had physical therapy for it, and now, apart from a l...