Far too frequently, when someone finds out that I advocate eating a single meal a day, the question is posed as to how one can possibly get their daily complement of calories in a single meal? The question never fails to take me aback, although by now, I really should be used to it. After a bit of back and forth with the questioner, the problem is always revealed to be implicit assumptions as to what caloric intake one ought to strive for, with the questioner always pegging caloric intake much higher than I would.
Who Are You, and Why Are You Fasting?
Given the reach of the internet, for all I know, this blog may be quite popular with the canine crowd.
Be that as it may, when I write posts relating to fasting, I have a fairly clear picture in my mind about my target audience, and my foundational assumption is that it isn’t comprised of dogs, but, rather, mostly real people.
Along with their assumed humanity, I also assume that the person seeking to fast is generally healthy. Despite the fact that there has been considerable research that supports the notion that fasting is beneficial for some pathological conditions like cancer, in general, I’m going to assume that you do not have any serious medical conditions that would serve to complicate things.
Further, at least when it comes to pegging daily caloric intake on the high side, I’m going to assume that you are male … sorry ladies. Women in general tend to err on the side of eating too little. All told, then, the basic assumption is that you probably are a relatively healthy male. That’s a good starting point, but I also make assumptions about which one of these guys you are:
I‘m fairly confident asserting that you’re probably not the guy in the picture on the right, that is, you are not an athlete. Now this is probably a good thing, because the guy in that picture is Michael Phelps, and he reportedly eats 12,000 kCal while he is in training. Take a moment to let that number sink in, and realize that he eats almost an entire week’s worth of calories in one day ( based on the US RDA assumed 2000 kCal daily caloric intake ) Now, if, by some incredibly, outlandishly, outrageously small probability, you are Michael Phelps, I am very flattered that you read my blog, but please for God’s sake do not attempt to eat all that food in one meal. You won’t be able to do it, even with your prodigious talents, and you will probably undergo a not insignificant amount of pain and gastro-intestinal distress. Furthermore, as attested to by your tremendous success in the pool, you, your coaches, nutritionists, and the rest of your team obviously know what you are doing. If it ain’t broke…
In keeping with the “ain’t broke” philosophy, I am also pretty confident that you are not the guy in the middle picture, single digit body fat guy. If you , by some chance, are in that category, again, you probably don’t need me to tell you how to go about your body re-composition goals.
So that leaves us with the guy on the left. The average male, looking at 20+ % body fat, and with no real direction or plan for getting rid of it. You probably want to get yourself to look more like the single digit body fat guy, but you don’t really think that is a realistic goal, but at the very least you’d like to drop some of the fat. The particular guy in this picture got that way by eating six meals a day, training with weights with a push/pull/legs split three times a week, and eating PROTEIN at every meal, making darn sure to hit 3000 – 3500 kCals per day so as not to “lose lean mass!!”. At 6′ tall, 225 lbs., and 38 years old, things were not looking good. Now, I came to this remarkable degree of clarity about the average male because that picture on the left, that’s me in 2006. That was also me as recently as 2008, but, due to vanity reasons, I was not particularly willing to subject myself to shirtless pictures, so I don’t have them to post.
And there you have it, I’m generally assuming that you are close to the average guy end of the spectrum, and if I am near to the mark, then I suggest that what you fundamentally need to do is to decide whether your approach to things is working for you. And if you decide that your approach is flawed, then maybe, just maybe, your notions of what your caloric intake ought to be are off. Whatever else you may think of Jack Welch, he once said that one ought to “face reality as it is rather than how you wish it were.” And if you’re carrying too much body fat, then it may be time to consider that your caloric intake had a hand in creating that reality.
Semi-Starvation Level Caloric Intake
It is pretty much a given that any political discussion, if it goes on long enough, will eventually culminate with someone invoking Adolf Hitler or Nazis. In very much the same way, discussions regarding calorie restricted diets will devolve into accusations and recriminations regarding starvation level caloric intake and the starvation response. But the truly fascinating thing about all of this is that in this particular case, Nazis and starvation level caloric intake are actually directly, unequivocally related!
In the late stages of the second world war, the allies were becoming increasingly concerned about the populations of Europe, and specifically, how to address the widespread starvation that they were sure to encounter in war ravaged regions. The amount of scientific literature available on starvation was very scant at the time, so the war department undertook a study using conscientious objector volunteers to undergo conditions similar to what the populations of Europe were being subjected. To this end they enlisted the help of the same physiologist that they had used to formulate the famous K-rations handed out as “food” to G.I.s, Ancel Keys.
The fact that the principal researcher was Ancel Keys should give us all pause. Recall that Keys is the man who manipulated his results to point the finger at dietary fats as the cause of atherosclerosis. But let’s not accuse him of anything here, we’ll just keep that in the back of our minds and proceed with caution. Keys and colleagues fed their subject a diet that comprised ~1800 kCal per day for 5 months, at the end of which all participants had lost about 25% of their starting body mass, and looked more or less like this:
The picture is pretty shocking, and it ought to make all of us interested in maintaining lean body mass very very afraid of an 1800 kCal intake for a period of 5 months. Once we get over the initial shock, however, and we start to think about what this all means, things get suspicious very quickly. Assuming that the average month is 30 days long, 5 months comprise a period of 150 days, or approximately 21.5 weeks, which means that a 25 lb. weight loss over that span is actually a weight loss of 1.2 lbs. per week, or in other words, the currently accepted reasonable weekly weight loss target:
Now, I’m not holding Jenny Craig up to be the epitome of scientific thought on nutrition and caloric restriction. I do, however, expect that as a rational profit seeking enterprise, they would not make such a guarantee unless they were fairly convinced that they would not have any difficulty in materializing the promised weight loss. Moreover, if they made a practice of regularly starving their clients, I don’t expect that they would be in business very long. So, these folks in the starvation study were clearly different than their modern day equivalents. When we realize that a 25 – 30 lb. weight loss represented 25% of the starting mass of these two men in the picture, we immediately start to see what that difference might be. The gentleman on the left in the picture would have had to start out at a body weight of 100 lbs. in order that a 25 lb. weight loss would represent 25% of his total mass. Now, maybe the numbers are wrong and he only lost 20% of his mass. That still makes him a tiny wisp of a man of 120 lbs. Any way you slice it, he certainly did not start out looking like me in 2006, or what I presume the average male reader might look like.
Based on this research, Keys came out with a 1300+ page tome in 1950 entitled “The Biology of Human Starvation”, so you might be forgiven for thinking that what he actually did was feed subjects a severely calorie restricted diet and record the results … i.e. study human starvation. But that’s not exactly what he did. In fact, he first stuffed his subjects with a diet comprised of ~3200 kcal per day over the course of three months. For a man weighing in at roughly 100 – 120 lbs., that’s a grotesque amount of calories. He then cut their calories in half for the successive six months. So, is it possible that metabolism will come to accommodate excessive caloric intake by being less efficient as a result of gross overfeeding? Would results have been different with subjects eating 2000 – 2500 kcal per day? What if there had been no initial intervention at all in the men’s caloric intake, that is, they were left to feed ad libitum? Would the results have been different if subjects were eating at a 25% reduced calorie level rather than the 50% in the study? We cannot know, for Keys didn’t do any of this work.
But recall that Keys’ study was commissioned by the army, and they had a very specific question that they wanted answered. They did not care about the mechanisms of starvation per se. Rather, they were interested in knowing more about the conditions that they were likely to have to deal with in war torn Europe. As such, Keys fed his subjects a diet representative of what was available in German occupied cities: i.e., potatoes, turnips, rutabagas, dark bread, and macaroni, all foods that are not particularly noted for their protein contents. In fact, if participants were eating the most protein dense food on that list, dark rye bread, they would be getting about 50g of protein per day. So maybe a fundamental question is whether the Minnesota experiment tested the effects of a semi-starvation level of caloric intake, or whether it tested the effects of chronic protein deficiency? Naively, to me the men in the picture certainly do look like they were cannibalizing muscle tissue to make up for some deficiency.
And there’s yet more. These men were not simply fed a calorie restricted woefully protein deficient diet. Rather, researchers intentionally intervened in the diet if subjects were not losing weight at the expected 2.5 lbs. per week:
So Ancel Keys did something that was going to prove typical of the way that he approached science. He could have gathered a number of subjects together, and fed them the typical foods available in the German occupied cities at a variety of caloric intake levels in an attempt to determine what constituted a starvation level of caloric intake. But he did not do this. Far from it. Instead, he decided what a starvation level of caloric intake was, a priori, and then he set about administering this to his subjects, and further, when subjects failed to respond in a way consistent with his assumptions, rather than adjust his assumptions, he moved the goal posts.
One more thing. We know that the response of the body to prolonged starvation is to involuntarily lower metabolic rate, as well as for a voluntary reduction in activity and thereby a reduction in voluntary energy expenditure. Keys saw to it that his subjects could not do this as participants were expected to expend 3000 kcal per day. This was accomplished principally by performing chronic cardio … walking on treadmills. I can’t think of a better way to ensure that upper body musculature would be sacrificed to maintain functional lower extremities.
For being the seminal work on the biology of human starvation, Keys’ work leaves a lot to be desired. The basic takeaway from all of this, then, is that if your notions of what constitutes a semi-starvation level of caloric intake are in any way based upon the Minnesota Starvation Studies or on “The Biology of Human Starvation”, then they are most certainly wrong.
A Different Perspective
What if we were to take in a “semi-starvation” level of calories, but instead of a chronic protein deficiency, we ingested, say … 1.5 g of protein per kg of body weight, and made the rest of the caloric intake up via fat? Further, it would would be really interesting if we would engage in resistance exercise rather than chronic cardio. It would be really interesting if someone were to try that. Luckily for us, I did.
For five weeks at the end of last year, I took in approximately 1500 kcal. per day in one evening meal, making sure to get at a minimum 1.5 g of protein per kilogram of bodyweight. The remainder of my calories were made up of fats with some incidental carbohydrates in the form of fibrous vegetables. In terms of exercise, I was doing the Armstrong pullup program. Over the course of those five weeks I dropped around 7 lbs. For my efforts, this was me Christmas Eve, 2012, circa 178 lbs., Ancel Keys be dammned:
Irrespective of my results, you may still think that your particular metabolism dictates a higher caloric intake, and for all that I know, you may be right. When it comes to your metabolism, you are the ultimate arbiter. Yet, if you keep trying to shed fat, and it’s just not happening … could it be your caloric intake, maybe?