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

What $115 Buys--Junk Food vs. Real Food

A lady recently went off about how little food $115 buys, complaining that the pile of (mostly) junk food she bought wouldn't make a week's worth of lunches and snacks for her children. Sad to say, but this looks like what I see in a lot of grocery carts.  Fat pic.twitter.com/qbM23ydaOq — shellshock (@shellshockkk) March 7, 2025 Coincidentally, I paid almost exactly the same amount today on groceries that would make lots of healthy lunches. It's filling food that won't leave you hungry every few hours for snacks. If we want to make America healthy again, this is the way.  

Celebrities Shilling for Big Soda

There's a push in Washington and ten states to ban soda (and other junk food) from SNAP, a program for low-income people to buy groceries. This seems like a no-brainer: the N in SNAP stands for nutrition, and soda doesn't have nutrients. It's liquid sugar, the last thing we need in a country full of diabetics. People can drink water for virtually nothing and save their SNAP money for actual food. Yet a number of posts from otherwise sensible accounts have opposed this.  Reporter Nick Sorter says that a company called Influenceable has been paying influencers to post these opinions. (Click on the link for the full thread.) 🚨🧵 EXPOSED: “INFLUENCEABLE” — The company cutting Big Checks to “influencers” on behalf of Big Soda Over the past 48 hours, several large supposedly MAGA-aligned “influencers” posted almost identical talking points fed to them, convincing you MAHA was out of line for not… pic.twitter.com/PpPwH9lHGe — Nick Sortor (@nicksortor) March 22, 2025 Sorter adds...

$17/pound chips! Real food is cheaper

 My latest video on YouTube: Real food is generally cheaper than junk food--the pictures prove it. I took these at Kroger and from their website in March 2025. Prices are either straight from the tags or calculated based on product weight.  Music: On We Go (ClipChamp)  First photo by AS Photography: https://www.pexels.com/photo/vegetables-stall-868110/

Not Only Cheaper, But Easier

A while back, I wrote about saving money on break time coffee and snacks. I haven't done very well putting it into practice. But a post by James Clear today got me thinking about it again: Warren Buffett uses a two-list system to prioritize things. Check it out --and follow the instructions. Using Buffett's two-list system, two of the goals I ended up with were taking care of myself and saving $400 more per month than I already am. As I said, I've been wanting to save money, and the system made me really focus on this. I came up with 11 money-saving ideas, six of which had to do with food. Buying hamburger in bulk. Ranch Foods Direct sells one-pound packages of 80% lean pastured ground beef in bundles of 20 for a lot less than Whole Foods. Sprouts only carries super-lean beef that's grass-fed, and it's more expensive, too.  Not driving to Whole Foods. Whole Foods is out of my way, and saving a weekly trip saves gas. Coffee at home, tea at work. Tea is fr...

1972: Carole King, M*A*S*H and...Food for 2014?

I feel well enough to try Atkins induction again. The palpitations are gone, even without taking potassium. My energy level is back to normal--no more trucking on the treadmill early in the morning  to burn off nervous energy or emergency meat, cheese and mineral water stops after yoga. It's back to lounging around to Chopin and Debussy in the morning and stopping at the wine bar for pleasure. I'm using the original Atkins book: Dr. Atkins' Diet Revolution from 1972. While looking in the book for a way to make gelatin (which is allowed on induction, but Jello(TM) and products like it have questionable ingredients), I felt the earth move under my feet : those recipes from 42 years ago look delicious and they're mostly real food. It makes sense, though: the cooks who wrote the recipes probably didn't have had a palette used to low-fat food full of added sugar or a bag of tricks to make low-fat food edible. Anyone who writes a recipe called "Cottage Cheese and...