Explanations for Blood Sugar Rise with Protein Consumption

Here’s my questions/comments for the KetoGains thread on this subject.

I’ve been trying for a while to wrap my head around this subject. Here’s what I think at the moment. Would welcome any feedback on where I am missing it.

1 – My blood sugar meter shows that my blood sugar goes up 25 points with Protein (50g of whey) for a couple of hours. Not a bad increase since it’s only from 85 to 110 (US units). I have documented this at: http://lowcarbstudies.com/blog/2018/03/29/blood-sugar-response-to-proteins/ .

2 – My blood sugar drops fairly rapidly at the end of the two hours (makes me hungry) which decreases when the blood sugar levels out. As long as I keep that in mind and keep food out of reach in that time frame I am OK. Otherwise, it seems like my body is telling me that it wants is ready to eat more Protein (or just food).
3 – Blood sugar production proceeds at a constant rate which isn’t all that much affected by Protein consumption. I’ve seen enough studies to believe that is probably the case such as (Claire Fromentin, Daniel Tomé, Françoise Nau, Laurent Flet, Catherine Luengo, Dalila Azzout-Marniche, Pascal Sanders, Gilles Fromentin, and Claire Gaudichon. Dietary Proteins Contribute Little to Glucose Production, Even Under Optimal Gluconeogenic Conditions in Healthy Humans. Diabetes 2013 May; 62(5): 1435-1442.). Also, the demand vs supply GNG argument seems strong. This rules out the idea of GNG being increased by the Protein.
4 – In a non-diabetic blood sugar doesn’t rise as much with ingested Protein as it does in a T2 Diabetic. It may not raise at all. I plan on an experiment with a “healthy” friend to confirm this for myself although the studies say it is “minimal”. But is that difference due to broken Insulin Resistance in the T2 Diabetic? As the Insulin goes up to deal with the Protein does that increase the Insulin Resistance of the cells at the same time and block the glucose from being consumed?
5 – The failure for a T2 Diabetic seems to be able to reduce the production of glucose in response to consumption of Protein (or one of the downstream aspects of the consumption). The Glucose (argued above) is getting “backed up” in the process and not being disposed by Insulin since the Insulin is “busy” dealing with the Amino Acids (all in all a very good use of Insulin).

So although arguably Protein doesn’t turn into glucose directly since Protein does lead to a rise in Blood Sugar (in T2 Diabetics) then what difference does it make if it is increased levels of GNG or an inability to reduce the rate of GNG or due to Insulin Resistance? Either way, the result is the same, Blood Sugar goes up (for T2 Diabetics) with protein consumption.

So then the question for me is whether or not Blood Sugar going up by a relatively small amount in a keto dieter who is eating lots of Protein actually a problem? Normally, us diabetics are trained to do things to minimize their blood sugars. This notion is leading a lot of people to eat a lot of fat and less Protein than they probably should.

Put another way, does the advantage of eating more Protein (maintain or growing Lean Body Mass among others) outweigh the disadvantage (marginally higher blood sugars for short periods of time)?

Survey of the Scientific Literature

From an 20 year old article (Diabetes Educ. 1997 Nov-Dec;23(6):643-6, 648, 650-1. Protein: metabolism and effect on blood glucose levels. Franz MJ):

Insulin is required for carbohydrate, fat, and protein to be metabolized. … Protein has a minimal effect on blood glucose levels with adequate insulin. However, with insulin deficiency, gluconeogenesis proceeds rapidly and contributes to an elevated blood glucose level. With adequate insulin, the blood glucose response in persons with diabetes would be expected to be similar to the blood glucose response in persons without diabetes. The reason why protein does not increase blood glucose levels (sic: in a non-diabetic) is unclear. Several possibilities might explain the response: a slow conversion of protein to glucose, less protein being converted to glucose and released than previously thought, glucose from protein being incorporated into hepatic glycogen stores but not increasing the rate of hepatic glucose release, or because the process of gluconeogenesis from protein occurs over a period of hours and glucose can be disposed of if presented for utilization slowly and evenly over a long time period.

Questions raised by this article:

  1. They don’t define “minimum effect” so is a 20 point rise considered to be a “minimum effect”?
  2. Another study indicates that GNG is much more efficient in a Diabetic. Is that because of an Insulin deficiency (the way it is worded above)? Or is that due more to Insulin Resistance?

Here’s a curve from one paper which shows the body’s Insulin response to Protein vs Carbohydrates which shows that the body has a similar response to Protein as it does to Carbohydrates when it comes to Insulin Levels:

This seems to be a reasonable study (Claire Fromentin1,2, Daniel Tomé1,2, Françoise Nau3, Laurent Flet4, Catherine Luengo1,2, Dalila Azzout-Marniche1,2, Pascal Sanders5, Gilles Fromentin1,2 and Claire Gaudichon1,2. Dietary Proteins Contribute Little to Glucose Production, Even Under Optimal Gluconeogenic Conditions in Healthy Humans. Diabetes 2013 May; 62(5): 1435-1442.) which concludes:

We showed that after a normal intake of protein (20–25 g), the contribution of dietary protein to glucose production was small and did not exceed 10% of the total flux during the 8-h postprandial period, contributing the production of 4 g glucose to 50 g of total glucose production.

While that is true in healthy humans (the subject of this study), is it also true of Diabetic persons?

From one of the comments in this thread

Higher protein intake, which needs insulin response to get it where it needs to be, will increase physiological insulin resistance (adaptive glucose sparing) in order to get the protein into where it needs to go without pushing more glucose into the cells. this will result in seeing a higher fasting blood glucose, and lower circulating ketones, as they replace glucose as a fuel for the tissues that previously used more of it.

Here’s the pieces of the puzzle.

  • Body produces a relatively constant level of blood sugar
  • Non diabetics have little to no rise in Blood Sugar when they eat Protein
  • In a diabetic the down regulation of blood sugar in the presence of Insulin is faulty
    1. Eat Protein
    2. Body begins digesting Protein
    3. Pancreas increases Insulin production to push protein into muscle cells
    4. As Insulin goes up so does Insulin Resistance of the muscle cells to Glucose (difference between a diabetic and a non-diabetic)
    5. Because Glucose is not being disposed by the muscle cells as well, the level of Blood Sugar rises temporarily
    6. After the Protein is processed by the body the Blood Glucose drops

So the theory here is that while the blood sugar rises over the short term it is not being pushed into the cells.


Author: Doug

I'm an Engineer who is also a science geek. I was pre-diabetic in 1996 and became a diabetic in 2003. I decided to figure out how to hack my diabetes and in 2016 found the ketogetic diet which reversed my diabetes.

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