Mastering Diabetes

This is the name of a New York Times bestseller by Dr. Cyrus Khambatta and Robby Barbaro. I found it a fascinating read, and it would be an extremely helpful book for anyone with prediabetes or diabetes. Dr. Cyrus and Robby are themselves both type I diabetics, which they both acquired at a fairly young age, Robby at 12 and Cyrus at 22. Both were motivated in their career choices by wanting to be learn about their conditions and help others with diabetes, so Robby has a Master of Public Health and Cyrus a PhD in nutritional biochemistry. I found out about them when I saw them on Rich Roll’s podcast (I’ll talk about Rich’s story, chronicled in the book Finding Ultra, soon). I especially resonated with Dr. Cyrus because he got his undergrad degree from my department at Stanford, Mechanical Engineering.

The book explains why insulin resistance is the underline condition that must be addressed for all types of diabetes. I new that was true for prediabetes and the condition it can lead to, type II diabetes. I was surprised to learn how it is also crucial for type I. In type I diabetes. the part of the pancreas (beta-cells) responsible for making insulin has been damaged by an auto-immune condition, so the body cannot make enough of its own insulin. It becomes necessary to monitor blood glucose levels and inject insulin, for life. The technology is improving, there are now insulin pump and monitoring devices for blood sugar level. But it is still necessary to get externally applied insulin, and the better blood glucose is controlled, the healthier you are. The key point I was unaware of is that low insulin resistance is still very beneficial in controlling this condition. This keeps glucose fluctuations in the blood in a tighter window, and requires lower doses of insulin.

This came out dramatically in both Robby’s and Cyrus’s stories. Both were counselled to eat a low-carb diet, which seems logical on the surface, your body has trouble dealing with carbs, so eat less of them. In both their cases, this led to poorer glucose control, and needing higher doses of insulin over time. Only when they both independently discovered that a low fat whole foods plant based diet lowers insulin resistance did they get their conditions well-controlled. Now they have teamed up to teach their diet and approach to anyone with prediabetes or diabetes, and thousands have benefitted from their program, which is explained in the book.

Using a low fat whole foods plant based diet to improve insulin resistance seems counterintuitive. You’re going to fix a problem where the body does not tolerate carbs well with a higher carb diet? But I discussed this in a previous post on “Nutrition and Prediabetes“, making an analogy of the incoming carbs in our diet as the “tap” (as in a sink), and insulin helping glucose out of the bloodstream into cells where they are needed as the “drain”. Turning down the “tap” by eating a low-carb diet seems helpful, but it does not fix the clogged “drain”. But you can also turn down the “tap” by eating “good carbs”, which are processed more slowly, and at the same time unclog the drain, by eating a a low fat whole foods plant based diet.

This makes sense if you know that insulin resistance is caused by fat trapped inside muscle and liver cells, referred to as intramyocellular (“inside the muscle cell”) lipids or sometimes intramyocellular triglycerides. A low fat diet that emphasizes high quality plant foods (“good carbs”) helps the body flush out the fat trapped in the wrong places, which reduces insulin resistance. I also learned in Mastering Diabetes that it is relatively easy for dietary fat to enter muscle cells.

This does not give us license to eat any kind of junk we want as long as it’s low fat, because they are also part of the mechanism of driving up triglycerides, so are also implicated in insulin resistance, as pointed out on p. 105 of the book. So it’s important to eat a diet with high quality carbs, which is why whole food plant based is emphasized.

It is interesting to note that the diet promoted in this book is essentially identical to the one that has been used to reverse heart disease by reversing plaque build up in coronary arteries [1,2]. That is not surprising to me, as the point of Dr. Michael Greger’s book How Not to Die is that this diet helps for all the major chronic diseases of modern civilization.

I highly recommend Mastering Diabetes for anyone with prediabetes or diabetes. You can also find out more on the author’s website.


  1. Ornish, D, “Can lifestyle changes reverse coronary heart disease?: The Lifestyle Heart Trial”, The Lancet,, 1990.
  2. Esselstyn C, “A way to reverse CAD?”, J Fam Pract., 2014

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