Chris Horlacher presents a favorable review of a high protein/high fat diet in his recent blog post on fat consumption. In the interest of presenting a full range of viewpoints, I thought I might briefly discuss some of the counter-evidence, and make a recommendation for a balanced, common-sense nutritional plan.
As a type 1 diabetic, I differ remarkably from Horlacher. For one thing, my condition entitles me to regular consultations with professional dietitians. For another thing, being a diabetic exposes me to a daily risk of falling into ketosis, and I therefore question the wisdom of using ketones as an energy source. More on that in a moment. First, let’s take a brief look at protein.
Protein Absorption and Energy
There is a limit to how much protein the body can absorb. Excess dietary protein is inefficiently converted into glucose – which can be used for energy – ketones (more on them a little later), and ammonia, which is toxic and must first be processed by the liver and kidneys before being expelled from the body as urea.
The conversion of amino acids to glucose and ketones is not an efficient process. Because most people consume carbohydrates in some form or another, the body’s “first stop†for energy is the glucose metabolized from those carbohydrates. If a person’s energy needs are fully met by carbohydrate intake, whatever glucose has been converted from dietary protein is simply stored as body fat.
Fat storage is the body’s next stop for energy, but it must first be re-converted to glucose. During lengthy, strenuous exercise or other periods of rapid fat metabolization, calories from fat cannot always be used for energy (for technical reasons). The body resorts to ketones, a byproduct of protein synthesis.
Only if one’s energy needs are not met by carbohydrate intake and fat metabolization will the body move to alternative energy sources, such as protein. At this stage in the process, however, the only dietary protein being metabolized is whatever happens to currently exist in the blood stream. If little or none is present, then the body will metabolize muscle tissue to feed itself.
This phenomenon is not widely regarded as a healthy state of being. Trained distance runners, for example, must run in excess of two hours straight before their bodies resort to metabolizing muscle tissue. Pregnant women experience ketosis if they are not eating adequate amounts of carbohydrate or protein. Starving people experience ketosis, as do untreated diabetics.
Most people experience noticeable discomfort under such conditions. It is not pleasant.
Ketones
Inducing an emergency metabolic state that cannibalizes muscle tissue is, to put it mildly, a heterodox approach to health and fitness.
There is no question that inducing ketosis will result in weight loss. But is such weight loss healthy?
Consider the pictures below. On the left, you see yours truly at 135 pounds, in a state of advanced ketosis. On the right, you see me after six months of insulin therapy and getting between 50% and 60% of my total daily calories from carbohydrates. At that point, I weighed 148 pounds and was smack-dab in the middle of the recommended Body Mass Index range.
Ketosis: Before and After
High blood sugar – even extremely high blood sugar – poses no direct threat to the body in the short-run. It is long-run elevated blood sugar, on the other hand, that results in diabetic co-morbidities. For diabetics like me, it is ketosis that results in short-run damage. Left untreated, it becomes life-threatening and coma-inducing.
I could cite any number of scholarly journals here, but they are a mere Google search away, and sometimes a picture is worth many times its weight in words. What the pictures do not depict are the pervasive fatigue, constant dizziness, difficulty breathing, unbearable thirst, unyielding polyuria, increased heart rate and increased blood pressure I experienced as a direct result of ketosis. All of these symptoms are ready to return within hours of a missed insulin injection.
The point here is that, notwithstanding the associated weight loss, is damaging to the body. Much as tapeworms, poisoning, cancer, or stress all produce weight loss at the expense of actual health, so ketosis results in weight loss at the expense of the kind of damage I experienced between the months of July and October, 2009.
In fact, monitoring my body weight is an important responsibility I have as a type 1 diabetic to ensure that I am not experiencing ketosis.
As you can see, we diabetics view the idea of a self-induced, voluntary ketosis with extreme criticism. Non-diabetic advocates of low-carbohydrate diets, insulated from the immediate threat of coma, sometimes make excuses here. Because the long-term physical toll of ketosis does not also come with a 4-times-a-day insulin injection, perhaps they lose sight of the real long-terms risks to which they are exposed.
Diet, Weight Loss, and Health
All of this begs the question: Is mere weight loss the goal of all diets and exercise regimens, or is there something else to it?
I often find myself at odds with many in the pop-fitness community, who tend to recommend low-carb diets, weight training, and high-intensity interval training (HIIT) exclusively. Such advice centers around burning a lot of calories and losing a lot of weight. It makes for a great sound-bite, but what do you do once you achieve a healthy weight? Lose more weight? Burn more calories? Eat more protein and fat?
While some of us surely could stand to lose a little weight, not all people need to do so. Inducing ketosis in such circumstances defies medical science and common sense. Choosing the path that results in the greatest weight loss in the shortest period of time by no means results in an optimal health strategy, and losing a great deal of weight in a short period of time is often the sign of real medical problems.
It’s important to keep in mind the real goal of diet and exercise: long-term health. “Long-term health†means being fit and free of illness for decades. That means having a healthy and sustainable diet and exercise regimen, one that you enjoy, one that poses few long-term health risks. While no one may ever agree on the “correct” percentage of calories that ought to come from fat, protein, and carbohydrate, it is important to stay aware the serious health risks associated with abnormal metabolic conditions.
Good debate you guys got going here. Thanks for the article Ryan. What have you heard about the new 'miracle weight loss supplement' garcinia cambogia Im interested in finding one or two people with solid results in the first 30 days after their initial use and then interviewing them. If I snag the interviews, would it also be OK to come back here and do a guest blog post on the subject?
Alex
Ketosis and ketoacidosis are two entirely different metabolic states. You are confusing them. Ketosis occurs when the body utilizes fats as it's primary energy source, either from fat stores in the body, or from the diet. Ketoacidosis is a condition that occurs in diabetic patients when the blood sugar is too high, and causes the body pH to change, resulting in organ damage, coma and death. Insulin dependent diabetics can certainly survive and thrive on a very low carbohydrate diet. They must make sure, however, that they are providing adequate fats, and the right type of fats in their diet in relation to the proteins they are consuming. This type of diet requires careful planning. Some may tolerate it well, and others may not.
Inuits are dying early because of mercury poisoning
As a diabetic, its probably not smart for you to follow a ketosis diet. But, i am a personal trainer and a lot of my friends who are bodybuilders follow a ketosis diet. They claim it allows them to target fat stores, since their glycogen stores are depleted, without losing too much muscle mass. But none of them are diabetic or even prediabetic. I think it really depends on your pre-existing conditions when deciding whether or not a keto diet is good for you.
Ketosis is not dangerous for a person with a healthy metabolism. Ketoacidosis for a diabetic is.
While its true the body can store dietary carbohydrates, store dietary fats, however cannot store dietary proteins its not true "there is a limit to how much protein the body can absorb."
In terms of health we are discovering that its not as complex as a calorie is a calorie or low fat this and that. If I ate 2000 calories of cake I'd look a lot different than if I ate 2000 calories of a well balanced diet. Fats no different.
Its a bit more complex than that.
Ryan, please correct me if I'm wrong, but it sounds as though you are describing ketosis as metabolism of muscle…..but as I understand it, ketosis is using fatty acids as energy, no? If you are were burning up your muscle, you were beyond ketosis.
I also read your coments to Chris' original blog post. It is simply untrue that eating a high fat, "primal" diet cause kidney or liver damage, although I thinnk most experts would agree that protein is indeed toxic in high doses. The point of these diets is to get rid of the non-sense, insulin spiking (yes all food do indeed raise yur insulin to some level but to to the same extent) non-foods such as breads, pastas, and processed sugars. Our bodies are not adapted to eating them.
To me, it's actually amazing that eating a diet rich in animal fats, vegetables, nuts, and fruits, the exact things we have been eating for thousands of years is even a little bit controversial.
Questioning Ryan's conventional wisdom regarding high protein diets http://www.jissn.com/content/1/1/45#B4
Now you’re really reaching Ryan, you realize that using scientific qualifiers doesn’t immediately mean pseudoscience right? He’s implying a correllation where it’s perfectly reasonable to do so based on the evidence. The use of words like “probably”, “may”, “presumably”, “suggests” and “might” are commonplace in scientific literature.
Instead you’re cherry-picking singular sentences completely out of context in order to confirm your own biases. He’s not just guessing that ketones temporarily reduce blood pH (which other studies do show), and the statement that glucose is metabolized in preference to ketones is hardly a controversial statement at all.
Furthermore, he states nothing of the kind about DKA. He very clearly illustrates that there is a continuum experienced by diabetics that pass through ketosis and in to ketoacidosis. What he does say, though, is that only diabetics run the risk of going all the way in to ketoacidosis, which is completely correct. Your deliberate misreading of that section really hurts your case here.
I did go to your Google link, there’s nothing there suggesting a normal person undergoing ketosis faces any serious risk. As a Type I diabetic, you run the risk of going in to ketoacidosis and have spent your life diligently avoiding ketosis. But then you assumed that this condition remains true to people with normal pancreatic function, which is completely, 100% wrong. Being diabetic, you are an exceptional case here and the science fully understands why. But trying to create controversy and mystery where there simply isn’t any borders on mysticism and dishonesty.
While this is pertinent info for any Type I diabetics out there, it really only applies to them. Ketogenic diets certainly aren't abnormal or even unsustainable. Plenty of people have spent their entire lives in ketosis with no I'll effects to show for it. Eskimos, for instance, eat almost nothing but fat and protein their entire lives and have one of the lowest rates of heart disease anywhere. Indians, on the other hand, eat mostly carbs and suffer one of the highest rates. This isn't simply coincidence. There's anecdotal evidence of low-carb (or what history would consider normal) diets even curing Type II diabetes.
And yet the Inuit's life expectancy is 12 years lower than that of the average Canadian: http://www.statcan.gc.ca/daily-quotidien/080123/d…
Why would ketosis be healthy for non-diabetics but unhealthy for diabetics? Does that question not make you even a little curious? Why would something be so damaging to me and not to you?
There's more to life expectancy than just diet Ryan. The study is based on geography and so the more hostile climate just might be playing a factor. Similarly, Native Americans living on reservations also have lower life expectancies, but this is more related to the general state of poverty in those areas. Also, your statistics don't differentiate between Inuits following their traditional diet, and those who have adopted a more "westernized" diet. When you control for those two factors, the group that has deviated from the traditional Inuit diet have markedly poorer health. You have to look deeper at the facts.
And no, it's not curious at all. The mechanisms behind why ketogenic diets don't work for Type I diabetics are well known and documented. You can read all about it in "The Ketogenic Diet" by Lyle McDonald. He's probably the #1 authority on this and his book is used as a reference by nutritionists and dieticians all over.
http://books.google.ca/books?id=JtCZBe-2XVIC&…
Maybe you're right that the Inuit are a bad example here. Of course, they were not my example.
From the book you linked to (p. 34): "Type 1 diabetics have been found to produce up to 400 grams of ketones per day. The drop in blood pH seen in DKA is probably related to the overproduction of ketones under these circumstances."
His use of the word "probably" presents his case as conjecture, but "the overproduction of ketones" is what ketosis is, by definition.
Then further (p. 35): "The increase in ketone formation is coupled with an inability in the type 1 diabetic to use ketones in body tissue. Presumably this is because blood glucose is in adequate amounts making glucose the preferred fuel."
First "probably" and now "presumably." Pseudoscientific speculation is not research. First he wrongly proclaims that type 1 diabetics experience DKA exclusively, not ketosis. Dead wrong. Then he speculates that because diabetics have glucose in the blood, their bodies must *just prefer* using glucose instead of ketones – but lack of insulin is precisely what drives ketone production; our bodies don't prefer the glucose, in fact we cannot even access it in absence of insulin.
Further on p. 35 he openly states that ketosis stimulates the production of insulin in non-diabetic individuals. That is precisely the mechanism that drives insulin sensitivity, i.e. type 2 diabetes. Ketosis is therefore a contributing factor to type 2 diabetes.
I don't fault you for not being an expert in endocrinology and metabolism, but this citation does nothing to answer anything I've pointed out above. Please follow the "Google search" link in the text of my blog for further commentary on the risks of ketosis.
Correction: "insulin sensitivity" in the above comment should read "insulin resistance."
Why would a handful of almonds be a tasty and nutritious snack for you and deadly for me?
I also have a nut allergy. Diabetes is not an allergy to carbohydrates. The body's response is very different in both cases.
I understand that, but my point stands. Similarly I could have pointed to lactose intolerance or PKU or any other number of conditions. Differences in metabolic biochemistry clearly cause some substances to be innocuous or even healthy for one human being, while harmful or even deadly to another. Your assumption that because ketosis is damaging to you it must also be detrimental to non-diabetics is a non-sequitor.