Too Much Protein?

A ketogenic diet is any diet that puts you into ketosis. The issue isn’t only what raises your ketone levels but also what lowers them. It is glucose that keeps you out of ketosis and that generally means restricting carbohydrates. But glucose can come from other sources. This is where protein come in. It has been a common view that too much protein would keep you out of ketosis. The theory was that gluconeogenesis, the process that turns proteins into glucose, could interfere with ketosis. So, some have worried that too much protein was basically no different than too many starches and sugar.

That view has been challenged by more recent research. The newer understanding is that gluconeogenesis is mostly demand-driven, not supply driven. That said, it’s more complicated than that. There are conditions that can alter demand or else signaling. Benjamin Bikman, an insulin researcher, advocates a higher protein ketogenic diet. He says that initially it might matter when someone first goes onto a ketogenic diet, if they have hyperglycemia and hyperinsulinemia, a problem for far too many Americans. But as insulin levels are normalized, which can happen quickly, gluconeogenesis is not a problem.

So, it depends on how healthy you are. With insulin resistance, high protein intake might spike insulin and cause the insulin glucagon/ratio to become imbalanced. Yet for a person with a healthy metabolism, the glucose/insulin ratio might not change at all. As Ben Wagenmaker explains it, “Studies do show that GNG affects obese people and diabetics, in that excess protein produces measurable spikes in blood glucose levels, although this same effect has not been observed and quantified in non-diabetics that are not obese” (Gluconeogenesis, Chocolate Cake, and the Straw Man Fallacy).

Considering that most Americans are obese, diabetic, pre-diabetic or insulin resistant, it might be advisable to limit protein until one has become fat-adapted and metabolically flexible. It’s easy to figure out for yourself, though. You can simply measure such things and see how it is affecting you. Or you can go by an even simpler method. Once your body is regularly in ketosis, fasting should become easy. If you can skip meals or go a day without eating at all and not be particularly bothered by it, then you know you’re body has fully adjusted to ketosis. At that point, protein should no longer be a concern.

This is good to keep in mind, considering most people turn to specific diets later in life. Bikman points out that, as people age, the body requires more protein for health. That is because the body becomes less effective at using protein. And if you don’t get enough protein on a keto diet, the body will cannibalize muscle.  A lack of protein, in general, can be problematic — look at how lacking in musculature are many vegans with limited protein and lower quality protein. Muscle loss is a major health hazard for senior citizens, but muscle loss can begin much earlier in life.

* * *

Dietary Proteins Contribute Little to Glucose Production, Even Under Optimal Gluconeogenic Conditions in Healthy Humans
by Claire Fromentin et al

Dietary Protein and the Blood Glucose Concentration
by Frank Q. Nuttall & Mary C. Gannon

The relationship between gluconeogenic substrate supply and glucose production in humans
by F. Jahoor, E. J. Peters & R. R. Wolfe

More Than You Ever Wanted to Know About Protein & Gluconeogenesis
by Amy Berger

If You Eat Excess Protein, Does It Turn Into Excess Glucose?
by L. Amber O’Hearn

Protein, Gluconeogenesis, and Blood Sugar
by L. Amber O’Hearn

Ketosis Without Starvation: the human advantage
by L. Amber and Zooko Wilcox-O’Hearn

The Ultimate Guide to the Carnivore Diet:
How can carnivore diets be ketogenic when they have so much protein?
by L. Amber O’Hearn and Raphael Sirtoli

What is gluconeogenesis? How does does it control blood sugars?
by Raphael Sirtoli

the blood glucose, glucagon and insulin response to protein
by Marty Kendall

why do my blood sugars rise after a high protein meal?
by Marty Kendall

Gluconeogenesis – The worst name for a rock band ever
by Tyler Cartwright

Protein Over-consumption in Ketogenic Diets Explained
by Ken Adkins

Will This Kick Me Out Of Ketosis?
by Dustin Sikstrom

Keto Problems: Too Much Protein?
by Keto Sister

Dietary protein does not negatively impact blood glucose control.
by Bill Lagakos


5 thoughts on “Too Much Protein?

  1. I really like the hypothesis that type two diabetics and others who are not yet insulin sensitive may experience unwanted gluconeogenesis. I think it explains why some claim consuming “excess” protein is “no problem,” while others point to having difficulties. In other words, it’s yet another explanation of individual experiences differing. The other aspect, of course, could be burning protein for fuel vs kidney health, but that’s certainly been discussed a lot. In fact, my previous doctor warned me about increased metabolites when I was diabetic and had begun eating a lot of meat. Thank you for this collection of research and discussion, as this topic has been bugging me for a long time.

    I lost a lot of weight fasting, and burned away some lean mass because I was not doing HIIT or weight training at the time. I’ve spent considerable effort regaining, and frankly, I’ve been tending to a hip issue that could possibly have been a result of that. Thus, I’ve been trying to find my personal protein sweet spot while concerned about the possibility of consuming too much. My A1c is consistently great and my kidney stats are good (they’ve never been horrible, but I was diabetic, and the fluctuated when I started fasting and keto) so I’m not going to worry, though I’ll keep monitoring, as I have been.

    • This is a simple post. But the point made is fairly important, as it gets a lot of attention in keto debates. Unsurprisingly, your the first person to take interest in it. Most of my dietary writings like this rarely get likes or comments. Whereas publishing something political regularly bumps up the viewer count on the blog and often leads to much discussion in the comments section. To most people, a discussion of protein seems boring and irrelevant. Well, their loss.

      About the topic at hand, I have never personally had issues with protein excess, kidney problems, or diabetes. But I was concerned about my health, maybe prediabetic, when I turned to low-carb diet and eventually a ketoish diet, along with fasting and restricted eating periods. I did this simultaneously while doing aerobic exercise, HIIT training, weightliftng, and resistance training. I was gaining muscle while losing fat. Decades of severe depression also went away, as the amount of carbs went down further in shifting toward keto.

      Protein levels don’t seem to have any ill effect. I actually feel great on higher protein amounts. The main issue for me is fat intake. I do find fat to be highly satiating and so my diet is high-fat. But too much fat will give me diarrhea, especially if there is MCT oil involved. I decided to cut out MCT oil entirely, even though I liked the energy boost I got from them. I was a big fan of bulletproof coffee, which I’ve replaced with butter tea (I also add in some tallow, going by Paul Saladino’s advice). Do you enjoy bulletproof coffee?

      I go back and forth about including or excluding caffeine. As with sugar, I find it addictive. I’d eventually like to get to the point where my health, mood, and energy levels are at a high enough level that I won’t need to self-medicate with caffeine. That is how I got hooked on caffeine and sugar in the first place, to compensate for crippling depression. I’m still working on that. My mother tells me that my great grandmother used to put butter in her coffee and she grew up in rural Indiana, but then again she also put saltine crackers in her coffee which is not very keto.

      If you’re going to do a keto diet with protein restriction, there is pretty much no way to do it without upping the fat content to a major level. Otherwise, you’ll likely lose too much weight, have decreased energy, and experience declining health. One cannot live on only non-starchy vegetables and occasional low-sugar fruit. Simultaneously doing very low-carb and very low-fat seems like asking for trouble. I suppose it might work if one had a lifestyle with little physical activity and stress and if the little fat one was getting was really high quality and nutrient-dense.

      There is a reason vegans tend toward high-carb diets, as they have to make up for the lack of animal fat, although a vegan could consume large amounts of vegetable oils. It always seems strange to me why so many vegans also choose cut out fat. Plant-based oils may not have all those great fat-soluble vitamins, but relying on carbs never can be healthy long term. That said, there is a small but growing number of keto vegetarians, which can be done fairly well with nutritious dairy and eggs included. One of my vegetarian brothers has dropped some pounds by simply cutting out the starchy processed snack foods.

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