Tag Archives: Diabetes Solution

Do Tomatoes Have Too Many Carbohydrates?

Eat greens for vitamin K

Looks reasonable to me

Dr. Richard Bernstein wrote a great book advocating strict carbohydrate restriction for folks with diabetes.  I’m talking about a max of 30 grams a day, compared to 250–300 g in the standard American diet.

Dr. Bernstein cautions his diabetic patients and readers of Diabetes Solution to keep a tight lid on consumption of tomatoes.  An excerpt from page 149:

If you have them uncooked in salad, limit yourself to one slice or a single cherry tomato per cup of salad.

His concern is that tomatoes will raise your blood sugar too high.

That doesn’t make sense to me.  A 3-inch diameter tomato has 7 grams of carbohydrate, 2 of which are fiber.  So the digestible carb count is only 5 grams.  That’s not much.  So do tomatoes have a high glycemic index?  Unlikely, although it’s hard to be sure.  Good luck finding a reliable GI for tomatoes on the Internet.

I think Dr. Bernstein’s wrong about this one, which is rare.  I suppose it’s possible that tomatoes deliver some other substance to the bloodstream that interferes with carbohydrate metabolism, but Dr. Bernstein doesn’t mention that.

Do tomatoes play havoc with your blood sugars?

Steve Parker, M.D.

Dr. Bernstein: Effect of Dietary Protein on Blood Sugar

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.  It’s an important issue to Dr. Richard K. Bernstein, who definitely says it has to be taken into account.

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.
  • 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.

Dr. Bernstein wrote:

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-gatherer ancestors.

Conclusions

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.

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.