The Calories In / Calories Out (CICO) model is a frequent topic of discussion and disagreement here on PH and more widely. There are probably as many opponents as advocates of the model, and more heat than light generated by the discussions. The CICO card is also often played as a trump card in an attempt to close a discussion down or shut someone up, but to little avail. What's your take on the model, what do you see as its merits or deficiencies?
Gnolls (J. Stanton) has just posted a great article on his blog about the fallacy of the calorie concept for nutrition. He makes some very good points, such as:
- Our bodies are not steam engines
- There is no biochemical system in our bodies whose input is a "calorie"
- The fate of a "calorie" of food depends completely on its specific molecular composition, the composition of the foods accompanying it, and how those molecules interact with our current metabolic and nutritional state
Worth a read I think.
asked byeddieosh (1031)
Get FREE instant access to our Paleo For Beginners Guide & 15 FREE Recipes!
on January 11, 2013
at 10:31 AM
The CICO is absolutely true, it has to be, the First Law of Thermodynamics says it must be true. That's why it's called a "Law". Nobody sensible disputes this, not even Gary Taubes. It's also almost entirely irrelevant: it tells you HOW people get fat, but gives us no information about WHY people get fat.
This is what Taubes has to say:
"Say instead of talking about why fat tissue accumulates too much energy, we want to know why a particular restaurant gets so crowded. Now the energy we???re talking about is contained in entire people rather than just the fat in their fat tissue. Ten people contain so much energy; eleven people contain more, etc.. So what we want to know is why this restaurant is crowded and so over-stuffed with energy (i.e., people) and maybe why some other restaurant down the block has remained relatively empty ??? lean."
"If you asked me this question ??? why did this restaurant get crowded? ??? and I said, well, the restaurant got crowded (it got overstuffed with energy) because more people entered the restaurant than left it, you???d probably think I was being a wise guy or an idiot. (If I worked for the World Health Organization, I???d tell you that ???the fundamental cause of the crowded restaurant is an energy imbalance between people entering on one hand, and people exiting on the other hand.???) Of course, more people entered than left, you???d say. That???s obvious. But why?"
on January 11, 2013
at 09:18 AM
The CICO model is predicated on the theory of thermodynamics, specifically the first law: Increase in internal energy of a body = heat supplied to the body - work done by the body. This is taken to mean that if I put energy into my body in the form of food calories then the same amount of calories have to be expended by metabolizing the food and performing exercise otherwise my body will store these calories as fat.
I don't have any problem with the science per se, but I do take issue with the application of the model, and here's why. Proponents appear to unquestionably assume that the only control mechanism of calorie intake is the conscious mind of the individual, hence statements such as "eat less and exercise more if you want to lose weight". Failure to lose (and keep off weight) is therefore due to gluttony and sloth. None of this is helpful as it disempowers people, blaming them for their lack of willpower and branding them as sinners.
My conjecture is that the conscious mind is not the primary control mechanism for food consumption, and that the answer lies elsewhere. Taking evolutionary biology as our starting point, we could assert that the body has evolved a variety of strategies to balance food intake with energy expenditure, whereby the food consumed meets the needs of the body for growth, repair and procreation. There would be no evolutionary advantage to excessively over or under consuming food as the individual would suffer as a result (too much fat or not enough muscle would lead to immobility and the inability to successfully compete for resources), the human body has therefore developed mechanisms to control food intake, the main ones being hunger and satiety signals.
So, the CICO model is not necessarily broken, but it does get abused and has little utility when trying to understand more optimal approaches to nutrition. A better model would be one where we acknowledge the different mechanisms involved with food intake control, recognising that food type has a bigger role to play than the conscious mind: my suspicion is that the effect is around 80% food type and 20% mind. Rather than admonishing people to eat less and exercise more, a focus on what foods we eat is much more likely to result in positive outcomes. By applying our conscious minds to select foods beneficial to our health and avoid ones that are detrimental, we give our bodies the best chance of controlling calories consumed; in other words, respond to your hunger signals by feeding yourself nutritious foods and rely on your body to tell you when to stop.
on January 11, 2013
at 08:45 PM
Aaaah, one of my favorite topics -- partly because of its complexity and partly because of how divisive the discussion can become. Lots of passion on both sides of the belief system.
I think we all acknowledge what I like to call the Chinese Buffet Syndrome -- and no, I'm not talking about MSG. I'm talking about how you can have dinner at a Chinese buffet -- you load yourself up with food: soup, rice, noodles, egg rolls, chicken, vegetables, pork, you name it. You eat a plate, then a second, and maybe even go back for a third. You eat so much you practically have to be rolled out into the car and are so stuffed you are certain you won't eat again for at least three days. But then what happens? Two hours or so later, YOU'RE HUNGRY!! WTF!!
Now, this doesn't prove anything about CICO, but it does establish that (at least for some people), the amount of calories IN has nothing to do with satiety. (Or if it does, it's certainly not the only factor.) But was it just that it was too much food overall, or was it all the carbohydrate in the rice, noodles, and sauces made with sugar and corn syrup? Or maybe the big dose of protein on top of all that CHO.
I agree that all things being equal, CICO is correct. What most people seem to argue is that it's darn near impossible to balance those when we take into account the psychoactive properties and hormonal effects of wheat, sugar, and other refined CHO. They bypass our satiety mechanisms (in some people) to the point where our bodies literally scream out for more, and there comes a point where "willpower" and "just saying no" WILL NOT CUT IT. You want that cupcake, you need that cupcake, and dammit, you are going to have that cupcake. The "beauty" of lower-carb eating is that you get off the blood sugar roller coaster and can theoretically much better align the calories you ingest with the ones you expend.
But HERE'S one of THE BIG ISSUES, as I see it:
When we talk about "calories out," we tend to think only of exercise. How many calories do I "burn" on the treadmill, or the bike, or while I lift? Why do we never discuss calories out as ALL THE CALORIES WE BURN THE ENTIRE REST OF THE DAY? What matters more -- what you burn in an hour or so at the gym, or what your body is doing with fuel substrates the other 23 hours of the day?
Why do we never talk about all the "calories" our bodies burn to do ALL the other internal processes that require energy: digestion, breathing, our hearts beating, blinking, sitting upright, not to mention all the zillions of things we're not even aware of at all while they're going on constantly: sodium/potassium pumps that require ATP to pump electrolytes against their concentration gradients, for example.
So the big question is, why do some people seem to "burn" so much more energy--EVEN "AT REST"--than others? (In quotes because in light of what I just said above, our bodies never really are "at rest," even when we're sleeping.) Other people have included in their answers here the classic examples we all know of groups of people who can eat the same exact foods and do the same amount of exercise, yet some will gain weight, some will lose, and some will stay the same. What is happening inside these people, on a cellular level, that is so different as to cause these conflicting results?
And THIS is where I think the hormonal effects of food come in. For whatever reasons (lower muscle mass, different gut flora, different ApoE genotype, and on and on), some people seem better able to tolerate more carbohydrates than others, regardless of overt activity level. For people who have become insulin resistant, it seems that calories matter, but they have an awful lot of an easier time getting body fat off when they reduce CHO with the goal of keeping insulin levels low enough that most of their body tissues get the signal to start running on fat, rather than glucose. And NOW, now that they can finally access all those wonderful stores of fuel (stored body fat) that they were unable to access in the presence of high levels of insulin, they begin to correct the way their bodies use fuel round-the-clock. Not just when they're sprinting or lifting, but all the time. Insulin, leptin, what-have-you, level out the way they should.
This is "calories out," too. And it seems much more effective for some people to get a lot more of these calories out all day long at the cellular level when they cut back on CHO.
So when we talk about the example of the room getting full because more people are entering than leaving (like in borofergie's answer), we are still looking for how to get people to leave the room. Reducing carbs seem to do it pretty darn well in the metabolically deranged, in a way that's more effective than just cutting total calories.
on January 11, 2013
at 04:00 PM
CICO, as an equation, is perfect.
In a world of math and science numbers don't lie. There is no way to force the equation to be anything other than what it is. No matter how many times you run the numbers they will always give you the exact answer. There is no exception to that rule beyond changing your number system.
The problem that everyone has, however, is that human beings are not numbers. Despite their best efforts no one has ever come up with a universal equation to model a human being which is true for all humans.
The equation is perfect. The subject is far from it.
on January 11, 2013
at 03:00 PM
The problem with CICO is that its proponents generally assume that Calories Out is a matter of conscious decision. It's not. If you eat less, your metabolism will tend to go down, whether you want it to or not. If you eat more (and your metabolism is working properly because you have gotten off the SAD diet), your metabolism will tend to go up. Think of all the Paleo people who report that they suddenly have more energy.
Another way to think of it is: which are the independent variables and which are the dependent variables? The classic CICO view is that (i) you can consciously control the amount of calories you take in, (ii) you can consciously control the amount of calories you expend as energy, and (iii) what is left over is added as weight. Gary Taubes' great contribution is to point out that that is not how it works. Instead, (i) the amount of calories you take in is a matter of hormonal signals (and a certain amount of willpower), (ii) the body then decides, through hormonal signals, how many calories it wants to retain, e.g., as body fat, and (iii) what is left over is what your body lets you expend as energy. This is every bit as consistent with CICO, but there is a different view about what drives what.
Paleo is all about influencing (or, if you will, returning to a proper state) the hormonal signals that drive (i) and (ii). Traditional dieting is all about trying to overcome the messed-up hormonal signals that are causing problems in (i) and (ii) through willpower alone. That is why it is doomed to failure.
on January 11, 2013
at 12:53 PM
Broken? No. Simplified? Yes. Largely applicable? Yes.
At the most simple level CICO says weight change = calories in - calories out. It's sort of a law of nutrition. You don't violate it. But things like CI an CO are much more complex than the simplified law lets on.
CI??? The difference in macronutrients is real, but largely insignificant when put in the context of weight loss studies. Ultimately, the same caloric deficit regardless of reasonable macronutrient ratio produces the same weight loss. Gut health probably plays some role with how well we absorb energy, but again, on average, it doesn't.
CO??? Human calorie expendature varies a lot. This is probably why many folks claim that CICO fails. Hormones, metabolism, diet??? all affect CO.
So when you recognise that CI and CO aren't static simple inputs, but rather complex, dynamic equilibria, CICO doesn't appear to fail, it just gets too complex to be called a model anymore. I'm rather glad Robb Wolf made his recent post regarded carbohydrates recently. It really takes the woo out of the carbs-are-bad-fats-are-good argument.
on January 11, 2013
at 10:59 AM
It's not wrong exactly, but on its own it's way too simplistic. Not all calories are utilised by the same process, require the same supporting nutrients, or give identical hormone responses during metabolism.
It's a model for understanding something but its use is only as valuable as its level of inherent level of accuracy, which isn't as high as you would probably like.
on January 11, 2013
at 09:42 AM
The CICO model is inaccurate and does not make sense if you apply it (in my case for sure).
Different types of calories are metabolized differently. If you only eat fat which is very high in calories, you will lose weight. Does it make sense? It does, but not according to CICO model.
Some foods have the same amount of calories but different satiety index. What would fill you up more - a bowl of bone broth or one chocolate candy bar?
We all have different bacteria residing in our guts. Some bacteria (like my best friend Metanobrevibacter Smithii) "helps" people to extract more calories from the same amount of food. And you can't decrease the amount of it in your gut - it remains constant throughout your life.
If you feed two (or more) people the same amount of calories and same food every single day some of them will lose weight, some will gain weight and some will remain the same.
The counter argument is that if you eat too many calories every single day, you will gain weight (unless you are Michael Phelps). Yes, this is true. But it is more than just caloric input. It is the biochemistry of it. Animals in the wild should be fat - they have all the grass they can eat, 24/7. But they only get fat when they are fed by a zookeeper and live in captivity.
If it was a matter of calories, Oprah would be thin.
Good calories, bad calories - and it is not a book title. Bad calories wreck havoc in your system. Good calories nourish you (Terri Wahls). Good calories are whole organic seasonal grass-fed foods high in nutritional density. Bad calories are highly processed foods with low nutritional density. Species specific diet.
Yes, I know about the twinkies diet. Link One thing for certain - the experiment was not long term, we do not have his stool samples or his blood sugar results and other biological markers. He probably was losing weight because he was becoming a diabetic, if anything.
Six months old babies become obese when formula-fed. Yet they lose weight when breast-fed. Does baby formula have more calories than mother's milk?
My weight and my eating behavior have nothing to do with food, but everything to do with my gut bacteria. And I hate them with passion.
EDITED: For those who do not know: when we talk about living things, we need to take into account not just physics, but quantum biology and quantum math. Even though there is no quantum formula for caloric intake yet, people will discover it within the next ten years. Stop talking about thermodynamics - it is so 20th century!
on April 19, 2013
at 12:49 PM
The first law of thermodynamics applies to closed systems. We have ketones escaping our body through our urine and breath, undigested food comes out unused as well. We've all had a run in with a super greasy meal with a mad dash to the bathroom, and I'm sure we've all eaten corn. If the human body was a closed system, then the law would apply.
It's mostly true, but your guesstimate of how many calories you need could be way off. And our guesstimate of how many calories we need a day doesn't take into consideration of how the food will affect our calorie needs. I know when I drink too much, I don't move as much.
Finally, losing weight does not mean losing fat. The more paleo I go, the more weight I gain, and conversly, the smaller my waist gets. Calories in vs. calories out is the correct formula for weight loss, if you know your exact calories out. The formula for good health is way more complicated, which is why we have paleohacks.
EDIT*** By the way, after reading this, I saw a new post http://paleohacks.com/questions/192225/hack-my-stool-test-results-h-pylori-yeast-fat-malabsorption-dysbiosis#axzz2Qug08RKt
I didn't really want to know too much about a stool sample, but they mentioned their LCFA (long chain fatty acids?) was off the charts. That's a lot of unused calories that didn't get burned or stored!