Calories

When the conversation turns to diet and nutrition one of the first things to untangle is the oversimplified question: "how many calories should I eat?"     

Let's clear the air and establish some definitions of the two basic elements here. (Definitions from Wikipedia.)

Calorie - "Food energy is the amount of energy obtained from food that is available through cellular respiration."

The technical term for this idea that calories in minus calories out equals body mass is the"1st Law of Thermodynamics" - "an expression of the principle of conservation of energy, states that energy can be transformed (changed from one form to another), but cannot be created or destroyed. It is usually formulated by saying that the change in the internal energy of a system is equal to the amount of heat supplied to the system, minus the amount of work done by the system on its surroundings."

According to mainstream nutritionists these two ideas are all you need to know about nutrition to come to the conclusion that if you eat more calories than you burn, you get fat.  If you reduce the calories in and increase the calories out, you get lean and sexy.  Oh if it were so simple. 

Let's break this down a bit.  Here are two links to similar posts about similar things.  The first is from Dr. Eades, whom I look to for lots of great information regarding diet and nutrition.  The second is one of his sources for his post.  It's written by Robert McLeod, a physicist (one who would know very well the complexities of our second concept definition, Thermodynamics.)

Dr. Eades post here. http://tinyurl.com/363ld8s
Dr. McLeod's post here: http://tinyurl.com/afled9

I would like to just re-post them on here, because quite honestly there is not much to add.  What I'm going to try and do is add my comments to the discussion.

So let's look at the basics again.  Calorie is the amount of energy obtained from food that's available through cellular respiration.  A good question to ask, What's "cellular respiration" then?  "Cellular respiration, also known as 'oxidative metabolism', is one of the key ways a cell gains useful energy. It is the set of the metabolic reactions and processes that take place in organisms' cells to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions that involve the oxidation of one molecule and the reduction of another."

Meaning, it's a set of chemical reactions that food goes through in order to be converted into useful forms, mostly in the form of ATP since that is the most efficient fuel source of our bodies.  

The 1st Law of Thermodynamics says; energy (calories are energy from food) can not be destroyed only moved.  This is where most nutritional experts get the idea that it's basically the same as calories in-calories out = body mass.  But even on this surface this oversimplified equation misses.  In this equation we have energy minus energy = mass.  hahahaha.  They don't even have the same units.  It would have to be energy minus energy = energy.  You can't just switch the units from energy to mass!  

Ok moving past that, if you have to, this equation does nothing to describe the process breaking down the food into useful energy for us to use.  We are summing up incredibly complex processes into simple arithmetic.  That's not even funny.   

Applying the 1st Law to living organisms is Proof by Tautology. Yes, 1 + 1 = 2, but this tells us absolutely nothing about the underlying mechanics. The 1st Law does not (I repeat N-O-T) tell us whether you store excess energy in the form of fat, or bleed it off into the atmosphere by dilating blood vessels next to the skin, sweating, etc. To do so would require an accounting of entropy. - Robert McLeod

Again, the mechanics of energy use.  He goes on to demonstrate that the mathematics to account for all of this would be very, very difficult and the simple arithmetic of calories in minus calories out, just doesn't cut it. 

Ok, I just can't resist anymore.  Here is a copy of a large chunk from Robert's post regarding the thermodynamic argument or the calories in calories out argument.  I'm going to add some italics here where I see fit.  

One of Taubes' chapters deals with the idea that energy balance in humans can be reduced to the First Law of Thermodynamics:

ΔE = E_in - E_out

I was somewhat confused to see this Surely the nutritional scientists did not not really believe this, right? I mean, any idiot undergraduate students knows that the 1st Law is only useful in a closed system, and humans live on the planet Earth, not in an insulated box. Right?

Enter a rebuttal by G. Bray in the journal Obesity Reviews. Bray is a to be a major obesity researcher and one of the 2nd tier villains in the book. Taubes relates a story of Bray excising a section of a British report on obesity, where Bray removed the material pertaining to the relationship between insulin and obesity. He clearly has editorial support to make his case. Bray is one of the second-tier villains in Taubes' book. Taubes has a footnote (p. 421), which suggests that Bray actively suppressed the carbohydrate-insulin hypothesis.

* According to Novin, when he wrote up his presentation for the conference proceedings Bray removed the last four pages, all of which were on the link between carbohydrates, insulin, hunger, and weight gain. "I couldn't believe he would make that kind of arbitrary decision," Novin said.

Unfortunately, to a physicist this energy balance hypothesis looks like a silly hand-waving exercise, not a serious argument. Frankly I was flabbergasted when I first read this article. This conservation of energy argument is on the same scientific level as the ridiculous "drink cold water to lose weight" idiocy. A human organism is:

1. Not in thermal equilibrium with their environment. Last time I checked I have a body temperature around 38 °C and spend most of my time in 21 °C rooms.
2. Capable of significant mass flows (e.g. respiration).
3. Capable of sequestering entropy (e.g. protein synthesis).

Is wearing a sweater fattening (by insulating you from your environment)? Here's a quote from the rebuttal,

Let me make my position very clear. Obesity is the result of a prolonged small positive energy surplus with fat storage as the result. An energy deficit produces weight loss and tips the balance in the opposite direction from overeating.

According Bray's thermodynamics argument, wearing sweaters makes you fat. This illustrates the greatest fallacy of trying to apply the 1st Law to a human: it makes the implication that living organisms consume kilocalories for the purpose of generating heat rather than perform useful work (italics original to author) (i.e. breathing, contracting cardio and skeletal muscle, generating nervous action pulses, etc.). In reality heat is the waste product of basal metabolism. The first law does not distinguish between different types of energy. Heat, work are all equal under the First Law of Thermodynamics.

 Let me try and make all of this more simple.  At the end of the day, calories in minus calories out can't be true, because of these two glaring facts:
1. It only applies to closed systems, of which the body and humans are not.  A closed system would mean our body temps would be the same as the environment around us.  Like the example of the room above, our body temperature would be the same as the room temp, which it is clearly not.  This is why Robert makes the mocking statement that according to the thermodynamics argument, wearing a sweater would make you increase your fat storage, because if you increase the heat of your body, in order to balance out the equation your body would store fat.  This is not the case which means that we are not a closed system and the calorie argument is garbage.   
2. The math is oversimplifying complex movements of heat and energy and does nothing to explain how the metabolic process actually works in real life. 

So why does it work for some people?

Any ideas?  See my next post for an attempt at a simplified explanation of the metabolic process and my own theory of why a reduction in calories will reduce body fat levels.