I’ve been meaning to do a deep dive into physiological insulin resistance for quite a while now, but the universe keeps conspiring to take my time.  Because I haven’t had time to read, learn more and write about it, I thought I’d share the links I have accumulated thus far. Mostly because I’ve now been asked a variant of the following multiple times, or have seen the following posted on various forums for discussing nutrition, health, and low carbohydrate diets:

“Why has my blood glucose gone up on a low carb diet?”

Typically this is accompanied by a good deal of anxiety and fretting over glucometers.

I should know, I watched my blood glucose increase by a few points as I’ve sustained my low carb diet. My understanding is that this is a known adaptation completely unrelated to the insulin resistance concomitant with diabetes.

While I’m not the person you should ask about anything health related, I’ve wanted an answer to this question myself. The explanation I’ve read is that after going low carb, your muscle tissue becomes insulin resistant in order to preserve serum glucose availability for the brain. If your muscle tissue did not do this, reduced availability of glucose in the serum could (theoretically) put your in dire straights if your brain can’t meet minimal demand for glucose. (Mind you, even on a zero carb diet you can meet all your glucose requirements via gluconeogenesis. The point is, your body needs a way to tell your muscle mass to stop taking all the glucose it makes. This is that way.)

Because of this physiological insulin resistance,which I should mention is a benign state that is not making your diabetic insulin resistance worse, you wouldn’t want to take an oral glucose tolerance test while you are low carbing.

If you took a glucose tolerance test while on a low carb or ketogenic diet, you would fail. If you need to take such a test (and you want it to be accurate), increase your carbohydrate intake to ~150g for a few days and then take the oral glucose tolerance test.  The few days of increased carbohydrate intake will apparently let your body adapt to increased carbohydrate availability and your physiological insulin resistance will go away.

At any rate, that’s my extremely flawed, 2 minute brain dump on it based on a very limited bit of reading on the subject. For the record, I discussed my increased blood sugar with my doctor. I asked him if the explanation I gave above is the reason, and he indicated it was…but we didn’t spend a lot of time on this point.

If you are interested, here are some links that I started collecting on the subject of physiological insuline resistance. Not all are good sources, some are likely blind alleys, but they were part of my research notes, so I’ll share them in the Resources section below in the hopes that they will be of use to someone.

Resources

• Distinct Effects of Ketone Bodies on Down-Regulation of Cell Surface Insulin Receptor and Insulin Receptor Substrate-1 Phosphorylation in Adrenal Chromaffin Cells, Hiroki Yokoo, et al. The Journal of Pharmacology and Experimental Therapeutics, v304 994-1002. March 1, 2003.
• Physiological Insulin Resistance, Petro Dobromylskyj of the Hyperlipid blog.
• Physiological insulin resistance; Dawn Phenomenon, Petro Dobromylskyj of the Hyperlipid blog.
• Protons: Physiological Insulin Resistance, Petro Dobromylskyj of the Hyperlipid blog.
• Protons: Physiological Insulin Resistance Addendum, Petro Dobromylskyj of the Hyperlipid blog.
• Protons: Physiological Insulin Resistance Addendum Two, Petro Dobromylskyj of the Hyperlipid blog.
• Axen and Axen (4) Ketogenic insulin resistance. It’s all over now… , Petro Dobromylskyj of the Hyperlipid blog.
• Does Eating Low Carb Cause Insulin Resistance?, Mark Sisson of Mark’s Daily Apple.
• Dietary fat content alters insulin-mediated glucose metabolism in healthy men., Peter Bisschop et al. The American Journal of Clinical Nutrition, March 2001. Vol 73, n. 3 554-559.
• Effect of a controlled high-fat versus low-fat diet on insulin sensitivity and leptin levels in African-American and Caucasian women., JC Lovejoy, et al. Metabolism, Volume 47, issue 12 (December, 1998), p. 1520-1524.
• Comparison of the effects on insulin sensitivity of high carbohydrate and high fat diets in normal subjects, M Borkman, et al. The Journal of Clinical Endocrinology & Metabolism February 1, 1991 vol. 72 no. 2 432-437.
• A Conclusion to the “Safe Starch” Debate by Answering Four Questions, Ron Rosedale, MD. (blog).
• Is my blood sugar spike due to my unintentional low carbing?, PaleoHacks.
• How to prevent diabetes and heart disease for $16, Chris Kresser (blog).
• Why your “normal” blood sugar isn’t normal (Part 2), Chris Kresser (blog).
• Dear Pancreas, you may rest now… Glucose Tolerance Test Results, Diabetes Warrior blog.
• Need help with Insulin Resistance as a result of my Low Carb/VLC diet. Anything current?, PaleoHacks.
• Robb Wolf Transcript, Robb Wolf Podcast Transcript, See page 14!