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

Moving on to YouTube

Remember when the blogosphere was a wild ride? Doctors, writers and researchers dove into research, picked apart studies and stood up to official advice and conventional wisdom that didn't work. We found each other in the comments and made a community.  Along the way, Dr. T. Colin Campbell's research got exposed as shoddy by an English major, Tom Naughton made us laugh, "safe starch" fads made us scratch our heads, "Diabetes Warrior" Steve Cooksey almost went to jail, CarbSane trolled everyone who was anyone, and CarbSaneR trolled the troll.  Now it's very quiet. Blogs don't come up in Google search results anymore and even if they did, most of the bloggers have stopped writing.  That's why I've moved on to YouTube. Videos do come up in search results and my shorts--which are mostly what I make--get pushed out to hundreds of people or more. My videos are on food and health (biohacking), but also on growing things and fixing things. If you...

Palpitations Gone with Iron

Thanks to my internet friend Larcana, who alerted me to the connection between iron deficiency and palpitations, I doubled down on my iron supplements and, for good measure, washed them down with Emergen-C. It's a cold medicine with a mega-dose of vitamin C, plus B vitamins and minerals. I don't think vitamin C does anything for a cold (a friend bought the stuff and left it at my house the last time she visited), but vitamin C does help iron absorption. After doubling up on iron in the last three days, I feel back to normal. (I'd already been taking quite a bit of magnesium and potassium, so I probably had sufficient levels of those.) How did I get so low on iron? Maybe it was too many Quest bars instead of red meat when I had odd cravings during my dental infection recently. Maybe because it's too hard to find liver at the grocery store and I haven't eaten much of it lately. Maybe the antibiotics damaged my intestines . And apparently, I'm a heavy bleeder . ...

Holiday Dinner Tip from Restaurant Pros: Limit the Menu

After watching some people online getting freaked out about trying to put on holiday dinners and getting overwhelmed to the point that they're thinking about canceling the whole thing, I thought I'd put out a restaurant tip that will help people put on a dinner with less aggravation. A big complaint among the frustrated home cooks I've seen is that family members are not contributing to the dinner. But a bigger problem I see is that their menu is just too big. One lady's family is having her make 12 dishes all by herself, and some of these dishes look pretty complicated. Watch the video here or read on. The reason this is aggravating is that more dishes mean more shopping, more prep, and more cleanup. It's hard to make several dishes that will all be ready at the same time. Even though I used to be a prep cook at a restaurant, I've put on Thanksgiving dinners myself, and I cook from scratch almost every day, there's no way I'd try to make a 12-course di...

We Hate the ADA; Why does the Perfect Health Diet Get a Pass?

Some people keep touting the Perfect Health Diet as low-carb, but carb levels that are mostly in the triple digits aren't generally regarded as low-carb; in fact, one of the authors says low-carb diets are unhealthy. A lot of us hate the  American Diabetes Association's advice for diabetics: start with 45g to 60g of carbohydrate per meal and go higher or lower from there. That's 135g to 180g of carb. Perfect Health Diet advice for diabetics: eat 20% to 30% of your diet as carbohydrate. On 2,000 calories, that's 100g to 150g of carb. On 1,700 calories, that's 85 to 128g; on 2,200 calories, that's 112 to 168g. Depending on your carb and calorie intake, carbs would be 85g to 168g per day. That's not a mile off from the ADA's recommendations. Paul Jaminet, one of the authors of the Perfect Health Diet, says, "the basic biology here is that the body's physiology is optimized for a carbohydrate intake of about 30%." He warns against a ...

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...