Diet, Treatment

Ketogenic Diet and Hypoglycemia

ketogenic-diet-and-hypoglycemiaGrief had me wide awake at 3 a.m. on Saturday, I was trying to figure out which chores I could cram into the 14 hours before I returned to the land of migraine disability. I had admitted defeat with the ketogenic diet. One more meal was all I had left on the diet; dinner would take me back to migraine as usual.

Ketogenic Diet and Hypoglycemia: Cause and Effect

Frustratingly, even though the ketogenic diet reduced my migraine attack severity and enabled me to be more functional, it also caused hypoglycemia—which is in itself a migraine trigger. Despite a month of various fixes, I couldn’t get it under control. (I’ve actually been wrestling with it for two months. That awful nausea I attributed to dehydration was actually hypoglycemia. The wrung out feeling I woke up with each day was the fallout from hypoglycemia-triggered migraine attacks that came on while I slept.)

How I Discovered Hypoglycemia Was the Problem

After increasing to 2500 calories to gain some weight back, I woke up each day ravenous and shaky. This seemed odd—how could I be hungrier than when I ate 1700 calories a day? Knowing that a ketogenic diet could cause hypoglycemia, I began researching. Not only did I discover that it was likely I had hypoglycemia, but the nausea and accompanying symptoms of the previous month fit the pattern of reactive hypoglycemia perfectly.

Reactive Hypoglycemia

Reactive, or postprandial, hypoglycemia occurs two to four hours after eating. It’s usually a crash after eating a meal high in carbohydrates. Although I wasn’t eating many carbohydrates, my blood sugar was so low the rest of the time that I’d crash after my meal each day. It would start two hours after the meal, but I’m so used to ignoring vague physical symptoms that I didn’t notice until they got bad. Which they did like clockwork six hours after eating every night.

Treating Hypoglycemia

The treatment of mild hypoglycemia is relatively easy: eat small, frequent meals and eat a dose of carbs whenever your blood sugar dips too low. The latter was obviously out (it’s hard to dose up with carbs when you are limited to 15 grams a day). The former didn’t work for me either, since I still had a migraine attack every time I ate, so I could eat no more than two meals a day.

Desperately Searching for Fixes

I spent a month trying every possible fix I could imagine: increasing from one to two meals a day, eating the same ratio with less protein and more carbs, a lower ratio, 100 calorie snacks that didn’t seem to trigger migraine attacks (they did, the attacks just built slowly), eating more in the morning, 1 gram doses of sugar, more calories… Nearly everything worked for a day, then became ineffective. I tested my blood sugar so often that my fingertips developed callouses.

Magical Thinking

An idea came to mind a couple weeks ago that sounded like pure magical thinking: What if I increasing my ratio to 4:1 (that’s 90% fat) made the diet more effective and enabled me to eat small meals without triggering migraine attacks? I ran it past Hart and my naturopath. They both agreed with the magical thinking hypothesis.

Going for Broke

I didn’t give up on Saturday. I was clinging so desperately to the good hours that I decided to give the 4:1 ratio a shot before calling it quits. I began yesterday by cutting my protein in half so I could keep a relatively high carbohydrate content for the transition period. By evening, I felt remarkably good. I managed three 114 calorie snacks in less than three hours without a migraine attack. A migraine attack didn’t even come on in the night.

Today’s meal plan increased the protein and decreased the carbs some. Four 114 calorie snacks later, no migraine attack ensued and my blood sugar was fine (still on the low end, but manageable). Things went downhill when I ate an actual meal—it triggered a migraine attack and my blood sugar tanked. Several small snacks helped me recover and I’m up and thinking again.

Research Soothes My Worries (a Bit)

Today I learned that a person’s blood sugar range tends to be lower on a ketogenic diet than it normally is. Anything below 70 mg/dL is typically considered hypoglycemic, but 55-75 mg/dL is typical on a 4:1 ketogenic diet. This isn’t a cause for concern as long as the person doesn’t have hypoglycemia symptoms. Also, it can take a full week for one’s blood sugar to stabilize when starting on or changing a ketogenic diet. That means all my dietary tweaks have probably done just the opposite of what I intended. (I am not a medical professional—PLEASE don’t take my word for any of this information. If you’re struggling with a ketogenic diet and hypoglycemia, work with health care professionals to determine the best approach for you. I’m being very careful and consulting with doctors and dietitians as I attempt this unorthodox experiment. Still I worry my low blood sugar is causing long-term harm to my brain. I’m seeing an endocrinologist next week and am going to try get yet another opinion from a neurologist at an epilepsy clinic. Maybe then I’ll find peace of mind.)


Obviously, there are a lot of kinks to work out, but I feel like I’m getting closer to getting them sorted. Although most of my earlier fixes didn’t last long, they were all focused on increasing my carbohydrate content. Eating more frequent meals is a far more sustainable option—and one that seems like it could work. I’ve come close to admitting defeat countless times in the last two weeks. I have shed so many tears that I’m distrustful of possible indications of success. But the signs are promising, so I’m still hopeful.

16 thoughts on “Ketogenic Diet and Hypoglycemia”

    1. Hi Lisa,

      You can try eating smaller meals more frequently. Or you can increase your carbs a small amount and see if that helps. The smaller, more frequent meals did the trick for me.

      Take care,

  1. Kerrir, how did everything work out? Are you still doing half protein? Which ratios ended up working best for you? I am thinking of lowering protein and upping fat to 85% fat. 5% carbs. Eat butter in between? My sugars have been so low. Ive broken out with cystic acne and am dehydrated. How do I get my sugar back up from 46 safely??

  2. So glad you found a solution! Were/are you diabetic or did you ever have evidence of actually having periods of high blood sugar? I am not necessarily on keto but am having what I’m almost positive hypoglycemic episodes when I have the one two whammy of low carb and low sleep, and in the past migraines as well. I just started checking my sugars, my fasting is great as it was last time my Dr checked (low 80s) but today I ate a fairly high carb lunch (quinoa with a little fruit and veg making up carbs) and I felt fine but my level was 77 a little over 2 hours later which seems low for having had a higher carb lunch :-/ so I’m really curious to see what it is during an episode.. I have a feeling pretty low. I can never stomach the thought of drinking juice or anything plus as you mentioned you are trying to go low carb so that is beyond counterproductive 🙂 thanks for any insight.

  3. People. GLYCERIN for hypoglycemia symptoms. 1 tbsp in water. Immediate symptom relief. Zero effect on insulin or blood glucose. Miracle. Research Glycerin/hypoglycemia. That is all.

    1. Annie, glycerin is great unless you’re on an extremely low carbohydrate diet. This post is about when I had trouble with hypoglycemia on a medical ketogenic diet. I was limited to 15 grams of carbohydrates a day (for reference, a small apple has about 21 g). Using glycerin would have drastically reduced the already minuscule amount of vegetables and fruit I was able to eat.

      Take care,

      1. Kerrie, did your advisors state clearly why you would have to reduce the fruit & veg if you took glycerin? Just wondering what was the rationale.

        Take care, Gabriel

        1. Hi Gabriel, it’s because I was trying to keep my carbohydrate intake very low for the ketogenic diet. This isn’t normally an issue with hypoglycemia, just my weird needs!

          Take care,

  4. Did you finally stabilize your blood sugar on the 4:1 diet?
    I’m now 3 weeks into a keto diet and whenever I become hypoglycemic proteins makes me sick. The only thing that reliably helps is straight butter. I am looking for more solutions to enhance ketone creation as this seems to be what my body is reluctant to do-at least it doesn’t create them at the level required.

    1. Hi Melanie, yes, it stabilized after a few months. I was able to eat every two hours for a while, which helped a lot. I found a glucose monitor to be helpful, too. It kept me from letting my blood sugar drop dangerously low. Glucose monitors are relatively inexpensive though the test strips are pricey.

      If you’re not familiar with MCT oil, you may want to look into it. It won’t help with hypoglycemia, but is thought to increase ketone levels.

      Take care,

    2. Did you find a solution? My BG is down to 46 after a meal. I also get sick with protein. Should I raise low blood sugar with carrots or broccoli? or stick it out with straight butter (this is what I would WANT to eat, but fear that will not be enough when BG is so low). Will it bounce back naturally if I only feed myself fat when that is happening? I probably just spiked myself and am keeping myself out of ketosis even longer..?

  5. Kerri, could you please elaborate on how you stabilized your blood sugars? I’m about 3 weeks into a ketogenic diet, and started frequently suffering from post prandial hypoglycemia (no migraines though…)


    1. Hi John, mine stabilized on its own after months. The typical recommendation for managing hypoglycemia is to eat small, frequent meals. That usually does the trick. I ate eight meals a day for about a month, but had to stop because I couldn’t deal with having eight migraine attacks every day.

      Take care,

  6. Your blood sugar swings (peaks and troughs) and your hyperglycaemia (higher blood sugar) will be damaging your brain! That’s why Alzheimer’s disease is called Diabetes type 3!

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