In my first book The Ketogenic Diet, I talked about something called the ketogenic ratio (KR) which is an equation/concept used in the planning of ketogenic diets for epilepsy patients.
The equation basically gives you the potential ketone producing potential of a given meal depending on the relative ketogenic or anti-ketogenic effect of the different macronutrients.
The question then becomes whether it matters or not for someone using a ketogenic diet for fat loss. A follow-up question is whether or not Ketostix, used to measure urinary ketone levels have any value for the general dieter. Let’s look at both topics.
The Ketogenic Ratio
So the KR of a given combination of nutrients can be estimated with the following equation:
Protein turns out to be partially ketogenic (46%) and partially anti-ketogenic (58%), reflecting the fact that some amino acids can be made into ketones, while other can be converted to glucose.
Carbohydrate is 100% anti-ketogenic and fat is mostly (90%) ketogenic. Tge 10% anti-ketogenic is due to the fact that the glycerol portion of triglycerides, explained in A Primer on Dietary Fats, can be converted to glucose in the liver.
Quoting from that section of The Ketogenic Diet:
This equation represents the relative tendency for a given macronutrient to either promote or prevent a ketogenic state (1). Recalling from the previous chapter that insulin and glucagon are the ultimate determinants of the shift to a ketotic state, this equation essentially represents the tendency for a given nutrient to raise insulin (anti-ketogenic) or glucagon (pro-ketogenic).
For the treatment of epilepsy, the ratio of K to AK must be at least 1.5 for a meal to be considered ketogenic (1). Typically, this results in a diet containing 4 grams of fat for each gram of protein and carbohydrate, called a 4:1 diet. More details on the development of ketogenic diets for epilepsy can be found in the references, as they are beyond the scope of this book.
So that’s what the KR is. The next question is whether or not its relevant outside of epilepsy treatment.
Problems with The Ketogenic Ratio
However, invariably when people tried to apply the KR to low-carbohydrate fat loss diets, one of two things happened. If the person set calories appropriately and used the KR, the protein intake ended up being far too low (because dietary fat had to be so damn high). Alternately, if they set protein appropriately and tried to scale dietary fat to the proper ratio, the caloric intake ended up being too high.
The former was a poor choice from the standpoint of protein sparing where sufficient dietary protein is absolutely critical. The second reduced or eliminated fat loss because fat oxidation was too low for the diet to be effective.
So basically I threw out the ketogenic ratio. As noted above, it’s crucial for the development of epilepsy treatment diets.
Anyone wanting more information on this topic should purchase the excellent The Ketogenic Diet: A Treatment for Epilepsy by Freeman, Freeman and Kelly.
But for dieters and folks seeking body recomposition, it made setting up appropriate diets impossible.
Ketosis and Protein Sparing
Additionally, there isn’t convincing evidence in my opinion that ketosis is crucial for the benefits of the diet. Yes, ketones are protein sparing but only when dietary protein intake is inadequate in the first place.
When protein is set appropriately (e.g. 1-1.5 g/lb lean body mass as discussed in The Protein Book), the development of ketosis isn’t that critical to spare protein. Simply, protein is the most protein sparing nutrient and other things (e.g. ketones vs. carbohydrates) only matter if protein is too low in the first place.
Even the hunger blunting effects of ketosis is up to debate and much of the recent literature on the topic suggests that it is actually the increased dietary protein intake that is causing the decreased hunger, rather than the presence of ketones per se.
Which is a long way of saying that I don’t think that the ketogenic ratio, or even the development of ketosis is important to the overall success (or failure for that matter) of low-carbohydrate diets. In the Ultimate Diet 2.0, I addressed this rather explicitly in a section titled “What About Ketosis?”
For the most part, I simply see ketosis as a “side-effect” of fat loss (burning to be more accurate), more than something to be explicitly sought out. That is, when you accelerate fat oxidation with the methods above, you tend to enter ketosis. Ketosis in and of itself isn’t any big deal.
For that reason, I won’t talk about monitoring ketone levels with Ketostix or anything like that. Frankly, using a low-carbohydrate/ketogenic diet for the fat loss phase of the UD2 has more to do with lowering insulin, raising catecholamines, and ramping up fat oxidation; ketosis is simply a tangential effect.
Ketosis and Fat Burning
A claim that is often made by keto zealots is that ketosis is required to cause fat to be burned or lost in the body. That is, they assert that ketosis causes fat burning. But this is incorrect. In fact it’s completely reversed.
Ketosis is not and has never been a cause of fat oxidation. Rather it is a consequence of fat oxidation. When ketosis develops, free fatty acids (FFA) are released from fat cells in high amounts and some of them are broken down and converted into the liver to ketones.
Fat oxidation leads to ketone production, not the other way around. Clearly diets that don’t induce ketosis cause fat loss just as effectively. That’s because ketosis is simply a consequence of fat oxidation.
Quite in fact, the excess build up of ketones in the bloodstream actually inhibits further fat mobilization at the fat cell. The body has three distinct mechanism to avoid the pathological buildup of ketones that occurs in runaway diabetic ketoacidosis. All three work to limit further fat oxidation or burning and this happens when ketones build up in the bloodstream past a certain point.
Are Ketostix Useful?
A question often asked by low-carbohydrate dieters is whether or not Ketostix should be used to monitor the diet. For background, low-carb dieters have often used a product called Ketostix which change color to indicate the concentration of ketones in the urine. You pee on them and they change color to indicate the presence or absence of ketones in the urine.
There are a number of problems with Ketostix not the least of which is that urinary ketone concentration is at best a very indirect indicator of what’s going on in the body. True ketosis is defined in terms of blood concentrations (terms ketonemia), not urine (terms ketonuria). But since you can’t easily measure ketones in the blood (no, you can’t put blood on the Ketostix, I tried it years ago and it doesn’t work), the next best thing is urinary ketones.
Now, obviously, if you have ketones in your urine, you certainly have them in your bloodstream. However, the absence of ketones in the urine doesn’t mean that you’re not still in ketosis (as defined by blood concentrations). You might be in ketosis as measured by blood levels but simply not be excreting any in the urine. Or not excreting enough to change the Ketostix.
Basically, there are a variety of things that influence whether or not there are enough ketones present to be excreted in the urine in sufficient quantities to make the Ketostix change colors.
For example, you might not be making ketones in sufficient quantities (this happens in lean people, especially if they are very active), lots of water can dilute your urine and the ketone concentration, some other variables can impact on whether or not you show ketones on the Ketostix.
As you might imagine, at the end of the day, I don’t think focusing on ketosis per se (or the lack thereof) or the Ketostix is very valuable. You can develop deep ketosis by gorging on dietary fat (especially Medium Chain Triglycerides) but your calories will be so high that you won’t be losing much, if any fat, that way.
And you can lose fat without ever showing a single ketone in the urine. Basically, there’s just no real correlation between ketosis, what the Ketostix are showing and fat loss.
Basically, I have seen too many dieters focusing on the Ketostix instead of what’s important: relative amounts of fat and lean body mass lost. Dieters should always focus on the latter. The goal of dieting is to lose fat while maintaining lean body mass/muscle mass. Whether your are in ketosis or not doesn’t matter