10 Reasons You Can’t Achieve Normal Blood Sugar on a High Carb Diet


This is an excerpt from Ahmed Afifi’s new book, From 10 to 5, My Journey with Diabetes.

Ahmed Afifi - BookMatching high carbs food with insulin is an impossible mission filled with inevitable uncertainty. And, the uncertainty is the enemy of control. I am not talking about the control of HbA1c of 6% or above which is possible with a bit higher percentage of carbs, but this is not the real control I am looking for. I am talking about the achievement of normal blood sugar of HbA1c below 5.5%.

Generally speaking, I followed the ADA guidelines of 45 to 60 grams of carbs a meal for about seven years. While living the high carbs life, I tried every possible way to get the required BS control. I mastered MDI techniques, learned all the factors (IC ratio, correction factor, insulin on board calculations), understood glycemic index and glycemic load, mastered correct timing of injections, close prediction of different foods’ digestion patterns, and I became a professional in carb counting. Unfortunately, none of these efforts got me closer to normal blood sugar. It was futile.

So, let’s discuss the discernible factors that make it impossible to control blood sugar while eating this amount of daily carbohydrates:

  1. One gram of carbohydrate raises the blood sugar of 150 lb non-obese T1 diabetic around 5 to 6 mg/dl. If he follows the ADA guidelines and eats around 180 grams of carbs daily, i.e. 60 grams of carbs per meal. These 60 grams of carbohydrates will rapidly raise his BS 300 to 360 mg/dl, which is a flood of glucose in his bloodstream. No insulin will catch or match such high and quickly elevated blood sugar.
  2. Any mistake in carbohydrates counting will lead to extra or less insulin injected. This mistake could be due to less experience, hidden carbohydrates in the meal or wrong labeling. Dr. Bernstein mentioned in his book that food producers are permitted a margin of error of ±20% deviated from their labeling of ingredients. In the case of 60 grams of carbs per meal, this 20% will lead to an uncertainty of ±12 grams of carbohydrates (60 * 20%). Multiply this by 5 mg/dl. The result will be an uncertainty of ±60 mg/dl in this man BS after eating. Therefore, if his BS was 100 mg/dl before food and injected equivalent units of insulin to the 60 grams of carbohydrates in his meal in order to reach 100 mg/dl again after food, this uncertainty will affect his BS result with ±60 mg/dl. So, instead of being 100 mg/dl after food, his BS will probably be either 160 or 40 mg/dl (100 ± 60). Imagine, if you eat more than 60 grams of carbs in one meal, what will happen then?
  3. With such amount of carbohydrates, any miscalculation in IC ratio (Insulin to carbs ratio) makes a huge mistake that will show itself via highs or lows of BS measurements after food.
  4. If fast-acting insulin is injected a long time prior to eating and food digested was delayed, your BS will drop then will rise again.
  5. If you inject fast-acting insulin closer to eating time and food was digested faster than expected, then BS will rise first then perhaps hypoglycemia will occur later.
  6. The higher the dose of insulin, the higher the uncertainty and the higher the loss in injected insulin units. This happens due to the immune system attack against big doses of insulin as per the law of insulin absorption by Dr. Richard Bernstein. The 150 lb person has an insulin correction factor of about 40 mg/dl (i.e. one fast-acting insulin unit lowers his BS about 40 mg/dl). For the 60 grams of carbs eaten, he requires 60÷5=12 units (assuming his IC ratio is 5). As per Dr. Bernstein, the uncertainty reaches 29% of the injected units in such large dose. i.e. 12 x 29% = 3.48 units, rounded to four uncertain units of insulin. So out of the 12 units of insulin injected, only eight units will be effective and the remaining four (or part of them) are destroyed by the immune system. This will create 4 x 40 = 160 mg/dl of uncertainty in BS expectations. So if you expect your BS to be 100 after eating it may reach to 100+160 = 260 mg/dl. As Dr. Bernstein said, “The result is totally haphazard blood sugars and complete unpredictability, just by the virtue of the varying amount of insulin absorbed”. Now imagine if the same person ate a low carb meal, the injected insulin should be much less and there will be almost no uncertainty.
  7. Uncontrolled diabetes causes gastroparesis as one of the complications. It means unpredictable digestion pattern. Consuming high carbohydrates meals, while gastroparesis exists, means you want to match FAI with unknown digestion pattern, which is impossible and will get the blood sugar profile out of control.
  8. If IOB (Insulin On Board) is miscalculated, you will see problems with BS after eating, either higher or lower than expected. This is a big problem, especially if the injected dose is high. For example, the IOB for three units of injected fast-acting insulin at the beginning of the third hour is only one unit, compared to IOB of six units for 18 units of fast-acting insulin injected. So the higher the carbs content in your meal, the higher the insulin dose, the higher the IOB in the third hour and the difficult the guesswork, if correction needed at the third hour.
  9. According to Dr. Bernstein law of small numbers: “Big inputs make big mistakes, small inputs make small mistakes”.[i]In other words, the smaller the carbohydrate content in a meal, the smaller the fast-acting insulin dose required, the smaller the expected mistakes and the easier to fix them. Conversely, the higher the carbohydrate content in a meal, the larger the fast-acting insulin dose required, the bigger the expected mistakes and the harder to fix them. Mistakes here means mistakes in guesswork, miscalculating injection timing in related to a meal, wrong carbs counting, digestion expectations, IOB calculation, wrong consideration of IC ratio, etc.
  10. The higher the BS will reach, the harder it is to bring it down, as insulin behaves differently when blood sugar is high. When BS rises, your body cells try to stop insulin from pushing extra toxic glucose into them, via making their insulin receptors resistant to insulin. Therefore, when your BS is 190 mg/dl and you want to get it down to 90 mg/dl, you will definitely use higher correction factor than if you are 120 and wants to get it down to 90 mg/dl. Myself I experienced this phenomenon many times in the era of my high carbs WOE.

If you are T1, T2 or even non-diabetic eating high carbohydrate diet and doubting what I mentioned above, I invite you to do the following experiment. Forget about measuring your BS two hours after a meal. Instead, for the next couple of days, measure your BS 30, 45, 60 and 75 minutes after eating high fast-acting carbohydrate meals and use your insulin maneuverability skills to match these meals, and then see for yourself what your BS numbers will be. The following couple of days, do the same thing but with low carb food. You are the judge.

[i]Bernstein, R. K. (2011). Dr. Bernstein’s diabetes solution: The complete guide to achieving normal blood sugars. New York: Little, Brown and Company, p, 102.

Read our interview with Ahmed Afifi!

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3 years ago

I’m sorry, this is very helpful information but the tone of this article is not as helpful. The best insulin regimen for a person is the one they can stick to, and expecting everyone with diabetes to become a keto person (which poses its own health risks) is just not reasonable. Of course, it’s not great to have blood sugar spike when eating a 60-carb meal, but if fasting blood sugar is managed well then the overall average should work out. An A1C below 5.5 is an amazing accomplishment but someone can lead a long, healthy life between 5.5 and… Read more »

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