Most diabetics don’t consider protein to elevate your blood sugar, out of ignorance mostly, but more diligent diabetics and especially those who are more in the know are much more concerned about how protein intake affects their blood sugar, especially those who do low carb diets.
So I read things all the time like protein turns to glucose, so that’s the reason why you want to limit your intake. It’s true that protein, or rather certain amino acids, can be turned to glucose by the liver, but the liver is capable of turning lots of things into glucose as needed, and without this we would not be able to survive without constant feeding, as we need glucose to live and in particular to keep our brains alive even when we don’t eat.
So there’s 3 main sources of this glucose, which is ingested glucose, stored glucose, called glycogen, and manufactured glucose, called gluconeogenesis. Some people who are actually pretty well read on diabetes claim that high protein in the diet increases gluconeogenesis by providing additional substrates for it, in other words the more protein you eat, the more gluconeogenesis you will get, and if you’re a diabetic, then this can put your blood sugar up.
Now some of these folks will actually claim that this is what happens to them, and in some people increasing protein will indeed raise their blood sugar. It’s important though to know what the heck is going on here when this happens, and by the way it’s not increased gluconeogenesis from the additional substrates this provides.
I read a really good article the other day on a ketogenic site, where they do get this, the surprising part isn’t that they understand it, it’s that keto people tend to be hell bent against high protein and strictly limit it to best create the ketogenic state they seek.
So a lot of keto people believe that protein turns to glucose by increasing the supply of substrates, but gluconeogenesis is driven by hormonal levels, not diet, and it can easily find all the substrates it needs even when you are in starvation, and that’s the point actually, to protect us against this. So if it wants amino acids it will get them, from your muscles if necessary, however that tends to only happen in starvation mode, as if you are eating then it doesn’t matter what you eat, the very process of metabolism will provide it with all it needs.
However, this still leaves us with the problem of people on low carb diets, and particularly on very low carb diets, claiming that a high protein diet increases their blood sugar. Well as it turns out this actually makes sense when we look at what happens when you eat protein and also eat a low carb diet, and this author has another article which looks at this, and this one is particularly impressive, and I did learn something from it.
Going back to the first article though, to set the stage for this, we see a chart from a study where they measured the degree of gluconeogenesis with people on a high carb, medium carb, and low carb diet. The subjects on the high and medium carb diet had similar rates of gluconeogenesis, but the lower carbers has a significantly higher amount, not an alarmingly higher one but 6.3 as opposed to 5.5, so 15% more.
This was done with normoglycemic subjects though, and since diabetics have a higher propensity toward gluconeogenesis, we’d expect the difference to be larger with us, and especially those of us who have much bigger issues with liver dumping. Personally I see a ton of gluconeogenesis when I do low carb, and my blood sugar goes up unacceptably high and stays there all the time.
The second article looks into why this may be, or at least provides a study which may shed some real light on this. We know that protein ingestion increases both insulin and glucagon and they are increased in balance so there doesn’t tend to be a net effect on blood sugar either way, which is the way this is supposed to work.
With people on low carb, and I’m talking the kind of low carb that produces ketosis, these people shoot for under 100 for sure and generally under 50, well we know that downregulates insulin secretion quite a bit actually.
So in a nutshell, the effect on blood sugar is going to have to do with the ratio between insulin and glucagon, so they measured both in low carb and non low carb subjects and found that with the low carbers, insulin didn’t go up as much but glucagon went up even more, and that will indeed produce higher blood sugar.
These were non diabetics though, but the same thing would happen to diabetics on this diet, and it actually would be even more pronounced, since diabetics have higher glucagon levels to start with. So now it makes sense for people to say well too much protein put me up too much, there’s only a minor increase in blood sugar with this in non diabetics, some diabetics do report more significant increases though.
Now this isn’t to say that people shouldn’t be doing the very low carb that produces these results, and it’s going to depend on the individual a lot, and there are people who thrive on these diets, strictly limiting both carbs and protein that is, which isn’t that easy to do but can be done by getting three quarters of your calories or so from fat, which can be done, although this is going to be a diet that is quite distinct from what most people are accustomed to.
So the distinguishing feature of this diet is indeed the high fat, and this is well known to increase insulin resistance, they admit that though but they say well the glucose load can be brought down so low that this doesn’t matter, which is true in some cases but in other cases, with those with a lot of excess liver dumping, this won’t happen, and what we end up with is high blood sugar anyway but more insulin resistance to go with it.
The biggest factor here is the way these diets downregulate insulin secretion, if you see the need for insulin decrease in concert, then this is actually a great result, but if your need for insulin remains, then you’re going to have some real problems here, and you can end up with persistently high blood sugar no matter how low carb you go, and lower may be worse with this.
So to sum up, the way we handle protein is going to depend basically on our carb and fat levels, less carbs and more fat make it more difficult to deal with high protein diets, but what we don’t want to be doing is just saying protein raises our blood sugar as a lot of people do. The truth here is, it depends.