Does Dietary Protein Affect Blood Sugars?

The protein in this can raise your blood sugar

I’m considering whether I should advise my patients with diabetes to pay careful attention to the protein content of their diet, assuming they’re not malnourished.  It’s an important issue to Dr. Richard K. Bernstein, who definitely says it has to be taken into account.

Protein can undoubtedly raise blood sugar levels.  But is the effect clinically significant?  Most  dietitians and physicians pay little attention to it as a source of hyperglycemia.  Here are some of Dr. Bernstein’s ideas pulled from the current edition of Diabetes Solution:

  • The liver (and the kidneys and intestines to a lesser extent) can convert protein to glucose, although it’s a slow and inefficient process.
  • Since the conversion process—called gluconeogenesis—is slow and inefficient, diabetics don’t see the high blood sugar spikes they would see from many ingested carbohydrates.
  • For example, 3 ounces (85 g) of hamburger patty could be converted to 6.5 g of glucose under the right circumstances.
  • Protein foods from animals (e.g., meat, fish, chicken, eggs) are about 20% protein by weight.
  • Dr. B recommends keeping protein portions in a particular meal consistent day-to-day (for example 6 ounces with each lunch).
  • He recommends at least 1–1.2 g of protein per kilogram of ideal body weight for non-athletic adults.  That’s more than the usual 0.8 g per kilogram.
  • The minimum protein he recommends for a 155-lb non-athletic adult is 11.7–14 ounces daily.
  • Growing children and athletes need more protein.
  • Each uncooked ounce of the foods on his “protein foods” list (page 181) provides about 6 g of protein.
  • On his eating plan, you choose the amount of protein in a meal that would satisfy you, which might be 3 ounces or 6–9 ounces.
  • If you have gastroparesis, however, you should limit your evening meal protein to 2 ounces of eggs, cheese, fish, or ground meat, while eating more protein at the two earlier meals in the day.

“In many respects—and going against the grain of a number of the medical establishment’s accepted notions about diabetics and protein—protein will become the most important part of our diet if you are going to control blood sugars just as it was for our hunter-getherer ancestors.”


I haven’t changed my thinking on this issue yet, but will let you know if and when I do.  I don’t talk much about protein in Conquer Diabetes and Prediabetes in part because I wanted to keep the program simpler than Dr. Bernstein’s.  Albert Einstein reportedly said, “Everything should be made as simple as possible, but not simpler.”

As with most aspects of diabetes, your mileage may vary.  The effect of dietary protein on blood sugars will depend on type 1 versus type 2 diabetes, and will vary from one person to another.  So it may be impossible to set rigid guidelines.

If interested, you can determine how much protein is in various foods at NutritionData.

Steve Parker, M.D.


Filed under Protein

6 responses to “Does Dietary Protein Affect Blood Sugars?

  1. So what is your thinking on this issue??

  2. Jim Jozwiak

    I think Volek and Phinney are the ones who nailed this concept. When eating low-carb, excess protein tends to raise fasting blood sugar and lower blood ketones. I am not a body builder or a serious athlete, but Bernstein’s protein numbers are too high for me when I eat low-carb; I need on the order of 0.75 grams of protein per pound of lean mass. However, when eating what might be construed as a Mediterranean diet, I don’t think protein really matters one way or the other; any effect is swamped by the carbs.

  3. Agree with what Jim wrote above…, I think you need to advise your patients to moderate their protein intake. I’ve cut back my protein consumption to the low end of Phinney/Volek’s recommend range and have been feeling betters with longer sustained periods of low fasting blood sugar and higher blood ketone levels.


    “Our last post described the evidence that the rate of gluconeogenesis (GNG) is stable under a variety of metabolic conditions. We also described several experiments in which large amounts of protein were ingested or infused and did not increase the rate. We concluded that eating more protein than your body needs probably doesn’t increase GNG.”

    I think it likely that for most people protein does not raise blood sugar – any more than glycerol from fats, which is also a glucose substrate, does – and for others, it may well do so. Also consider that many common proteins can be highly immunogenic foods and there is an immune component to diabetes.

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