Energy Balance Pseudoscience and Causality Hoax (2/2)

The messages I want to convey with this second part of the blog post are as follows:

  • To complete the explanations from the first part, which can be summarized as that the energy balance theory does not rightfully derive from the laws of thermodynamics. Energy intake and energy expenditure are not necessarily neither the cause nor the solution to the obesity problem
  • To clarify the causality fraud and its consequences in practice by means of a simple mathematical model of body weight dynamics, but also to explain the limitations of mathematical models.

I will use a very simple model of body weight dynamics, taken from an article (see) from Kevin Hall, a well-known promoter of the energy balance pseudoscience. In the past I have criticized the pretensions of this gentleman to interpret the forecasts of his mathematical model as scientific evidence, something always reprehensible but it is especially so in his case because he uses his results to blame the victims, the obese, for not being able to lose weight (see, see).

Please, do not bother criticizing the modifications I’m going to introduce in the mathematical model: I do not intend to propose an alternative model nor to improve the model. The ideas I want to convey are others and the model I use seems quackery to me, because instead of modelling the phenomenon of interest, which is the accumulation of triglycerides in the adipose tissue, what the model does is model the terms of the energy balance. Any model that is based on the energy balance theory is, in my opinion, insurmountable quackery (see first part of this entry).

Model #1: A model that lacks a physiological adaptation

I assume hereafter that the daily energy intake is as the picture below shows (it is the relatice change with respect to the baseline, which is supposed to be a point of intake&weight equilibrium):

The model is very easy to understand. The energy intake is the input (on the left side) and the body weight is the output (on the right side). Each day we calculate (yellow block) the difference between caloric intake and energy expenditure and, in this model, that value determines the daily weight gain. The body weight is calculated as the cumulative sum (orange block) of all these daily changes.

This model does not include a physiological adaptation mechanism.

In the graph below, on the left I show the body weight evolution with time and on the right the energy expenditure evolution. By design of this model, when the energy expenditure is reduced around 200 kcal/d the body weight will stabilize. It can be shown that when the energy intake is a constant the model stabilizes its output at weight=intake/epsilon, which in this case is -200/25.8 =-7.75 kg. There is no need to run the model to know that result because, as I said above, it is part of the design of the model.

We are not seeing a rebound effect (i.e. a physiological adaptation) because in the Model #1 we do not include a physiological adaptation mechanism.

Do we deduce from this simulation that the physiological adaptation does not exist in real life and that what happens is that obese people simply eat more than they tell us? (see).

Model #2: A model that does include a physiological adaptation

Let us suppose that, triggered by the food restriction, our physiology has changed. In Model #@ we maintain that there is a certain tendency to lose body fat, driven by the fact that we are eating too little, but now our adipose tissue has become especially prone to accumulate body fat (see the lightgray block and a new yellow block that adds these two effects in the figure below):

In this new version of the model, the body weight evolves as shown in the pictures below (blue curve on the left side). The energy expenditure is reduced as shown by the blue curve on the right side. The graph on the right shows that the simulated energy expenditure has been gradually reduced by around 50 kcal/d additional to what we expected (which would be the red curve):



In this model, the body weight is not regained by “eating more than it is expended”, but rather by the opposite, because the physiological adaptation that has been modeled is caused by the food restriction, i.e., for “eating an insufficient amount of food” in a sustained way. Does this model violate any laws of physics? Please consider that for our body functioning with the substrates that have not been stored is like we’ve just consumed a few grams less of food each day. It is not that hard to understand that Model #2 does not violate any law of physics or suppose an impossible situation for our body.

I believe there is no point in explaining how I implemented the physiological adaptation mechanism in Model #2. What I want to explain is that when I believe that there is a physiological adaptation and, therefore, I include an adaptation mechanism in the model, the model shows a physiological adaptation. And Model #2 is not doing anything clearly impossible: we are talking about an additional reduction of the energy expenditure of 50 kcal/d after two years. Note that the Hall calculations were that the CALERIE2 participants were consuming around 37 kcal/d more than they actually consumed (difference between black and white bars in the graph), which is a difference of the same order of magnitude of those 50 kcal/d that I have simulated. What the Hall model attributes to an increased energy intake when compared with actual data is probably caused by the physiological adaptation whose effects Hall despises.

In short, the message here is that when Hall argues that there is no physiological adaptation in reality because his model does not show a physiological adaptation, his argument is fallacious: if he included the appropriate mechanism in his model, his model would show a reduction of the energy expenditure that goes beyond his present prediction. Just as I have done. In short, his argument can be summarized as follows: “the physiological adaptation does not exist in real life because I did not want to include it in my mathematical model”.

This simulation illustrates the very long equilibration time for weight loss in obese subjects and demonstrates that the weight loss plateau observed after 6 mo cannot be a result of physiological adaptation (source)

Model #3: An “energy” model that does include a physiological adaptation

Model #3 is, mathematically speaking, identical to Model #2. It also includes a physiological adaptation mechanism, but the magnitude of that reaction now changes directly the total energy expenditure and the energy balance equation is applied to compute the magnitude of the daily body fat accumulation.

Note that the evolution in time of intake, energy expenditure and body weight are identical to those of Model #2, because mathematically models #2 and #3 are identical (it has only changed at which point of the feedback loop the physiological adaptation is applied). What is different between these two models is the assumed causality.

  • Model #2. Your adipose tissue stores more fat–> Your body has less fuel to spend–> your body reduces its energy expenditure
  • Model #3. Your body reduces its energy expenditure–> your body has more fuel to store–> your adipose tissue stores more fat

In Model #2 the adipocytes have changed their behavior and they seek to recover the lost body fat, and the rest of the body can not spend what has already been stored in the adipose tissue. Therefore, as a consequence of gaining weight, the energy expenditure is reduced exactly like in Model #3. A reduction in the total energy expenditure would only be a consequence of the underlying physiological process that is actually causing the changes in the accumulated body fat.

For the sake of clarity, these are the  weight (blue curve on the left) and energy expenditure (blue curve on the right) for Model #3:

The energy balance pseudoscience assumes that if you are regaining weight this is caused by an energy imbalance. What I am showing here is that other causalities are compatible too with the first law of thermodynamics: it is possible that the cause of gaining weight is a physiological adaptation regardless of the calorie intake or the energy expenditure. The adaptation can be driven by starvation, by losing weight, by a change in the mean size of the adipocytes or by another physiological cause. In this case, the energy expenditure would be an irrelevant possible symptom of the underlying physiological process that is indeed being caused by food scarcity. Model #2 does not violate any law of physics but it does highlight the causality fraud of the pseudoscientific energy balance paradigm.

it can be calculated that a weight loss of 20-kg body weight in an obese patient will result in an obligatory average reduction of 400 kcal in daily EE. Besides this obligatory or passive energy economy, further reductions in daily EE can also be expected as it has repeatedly been demonstrated that the fall in EE is greater than predicted by the loss of body mass, thereby underscoring the operation of mechanisms that actively promote energy conservation through adaptive suppression of thermogenesis. (source)

May be it doesn’t happen “through” suppression of thermogenesis: they are assuming that an effect is the cause.

How to avoid the physiological adaptation

From the point of view of the energy balance theory, if there is a physiological reaction equivalent to 50 kcal/d, if you eat 50 kcal less you will compensate for the physiological effect. But understanding the process requieres understanding causality: if the cause of the physiological adaptation were an excessive intake, reducing the energy intake would make the reaction disappear and the weight would remain stable. But the cause of that reaction is not necessarily that you eat “too much”, but rather the opposite. The adaptation may be caused by losing weight “eating of less”, i.e. by scarcity of food. If we confuse energy expenditure, a symptom, with the cause of weight regain, we will not prevent that weight regain.

What does the model predict if we even consume 50 kcal/d less? That the physiological reaction will continue to exist, because its cause is not an excessive energy intake. Reducing the energy intake is treating a symptom, the “energy balance”, not fixing the actual cause of that reaction.

I do not intend to draw any conclusions as if in real life there is or not a physiological adaptation similar to the one that I have included in the model. My message is exactly the opposite! What I try to explain is that no useful conclusion can be drawn from a simulation, about the existence or inexistence of such adaptation, because a mathematical model simply does what we command it to do.

And the other conclusion has to do with causality: if a factor makes us fatter, it has to make us fatter, not necessarily have a direct effect on our energy intake or on our energy expenditure. We save money for reasons that can not be deduced by examining the factors that affect our incomes or expenses.

Further reading:


Energy Balance Pseudoscience and Causality Hoax (1/2)

(versión en español: pinchar aquí)

Let us assume that your family unit saves 300 euros/month, the difference between the 2000 euros you earn at your job and the 1700 euros that you spend.

Savings = incomeexpenses

300 = 20001700

The above equation is correct, but “maths” tell us nothing about why you’re saving that amount each month. Income, expenses and savings are just numbers I can observe, but unless I know how your family thinks, unless I know your interests and motivations, I will not understand why you are saving 300 euros per month. The real cause can not be deduced from the knowledge of incomes and expenses.

Your savings are determined by your incomes and expenses. If you have no incomes you can not save!

This is a fallacy because it deceives drawing conclusions from conditions in which your behavior would be different. Of course if you have no incomes you can not save, but that is not the situation that we are talking about. We are talking about a situation where your incomes are 2000 euros/month and in that case saving is not mathematically impossible nor unrealistic.

Your  savings are determined by your incomes and expenses

It is typical of pseudosciences to use ambiguous terms (misleading language). These terms are introduced in the arguments with one meaning but, without prior notice, they are used to imply a different one. What you save each month can be “determined” (meaning “calculated“) from the knowledge of incomes and expenses, e.g. in the same way that the expenses can be computed by using a mere subtraction of incomes and savings. But, without prior notice, “determined” stops meaning that and it deceitfully starts to imply that changes in certain parameters cause changes in others. We should notice the difference between the following two statements:

You save because your incomes are bigger than your expenses

What you save can be calculated from incomes and expenses

The first one is correct but the second one is not necessarily so.

Why are you saving 300 euros/month? Maybe it is because your goal is to buy a car in the middle term. Is it possible that without that goal in mind your expenses could simply raise and match your incomes? Is it possible that if you planned to have a big expense in the future, you would accordingly reduce your expenses and increase your savings? The reasons why you save may have nothing to do with the magnitude of your incomes and expenses, unless you think of particular or extreme cases that are quantitatively different from the case under discussion. You normally save for other reasons and you consequently adjust your expenses.

Of course, it is also a possibility for a family to pay no attention to how much they save each month. In the absence of control, in the absence of regulation, the savings would be indeed determined by the difference between incomes and expenses. It is not impossible, but it is just a particular case, one where the parameter of is unregulated. It is only a possibility that may or may not happen, not the will of gods.

Of course I am drawing an analogy with the pseudoscientific energy balance theory. The defenders of this stupid theory believe that their ideas derive from an inviolable law of physics, but the reality is that what they defend is the idea that if suddenly your family starts saving 400 euros/month instead of 300/month, to understand why this change happened what we need to study is what determines your incomes or what determines your expenses. They even build mathematical models based on that stupid idea to try to understand obesity, instead of studying the physiological processes of triglycerides’ absorption and release (lipogenesis and lipolysis). Common sense tells us that the reasons why you save now more money can not be understood by means of studying the symptoms of that change.

The factors that determine the body fat accumulation may have no direct effect on energy intake nor in energy expenditure. A mathematical model of obesity based on the energy balance equation is just pseudoscience.

You visited recently a friend who has been hospitalized and as a result of that experience you changed the amount of money that you save per month. But, according to the “economic balance” theory, that visit can’t play a relevant role in your savings because it barely affected your expenses (a couple of euros of public transportation) and that visit doesn’t affect your salary

Even if we made a very detailed mathematical model of what determines the changes in incomes and expenses, we would be modeling the symptoms, not the phenomenon of interest, that would be the savings and the real causes of its behaviour. That mathematical model would be pure pseudoscience.

An imbalance between energy intake and energy expenditure will lead to a change in body weight (mass) and body composition (fat and lean masses). (source)

For example, the incidence of obesity and its co-morbidities has increased at a rapid rate over the past two decades. These conditions are characterized by changes in body weight (mass) that arise from an imbalance between the energy derived from food and the energy expended to maintain life and perform work.(source)

Mathematical models are beginning to provide a quantitative framework for integrating experimental data in humans and thereby help us better understand the dynamic imbalances of energy and macronutrients that give rise to changes in body weight and composition (source)

Obesity could be due to excess energy intake or decreased energy expenditure (source)

for insulin to cause fat gain, it must either increase energy intake, decrease energy expenditure, or both (source)

The fraud of the energy balance theory does not lie in the maths, it lies in the causality. The hoax is not the violation of universal laws, since the energy balance theory does not violate those laws, but the unwarranted assumption that the adipose tissue’s behaviour is passive or not physiologically regulated. Note that we know that there is a physiological regulation of the adipose tissue (see).

Why does no one propose to study muscle hypertrophy by using the energy balance pseudoscience? Is that so because the energy balance theory does not apply to energy accumulated in muscle mass? Is to eat more than you expend the way imposed by the laws of physics to increase our muscle mass? (see)

This is the end of the first part of this article. Read the second part.

Further reading:

Why the Energy Balance Theory is pseudoscience

Why the Energy Balance Theory is pseudoscience

First of all, its basis is a mere tautology (i.e. needless repetition of an idea) referred to the adipose tissue:

if the adipose tissue accumulates energy, in that tissue more energy comes in than gets out

This is just a truism, because that is what “accumulation” means, since energy can’t come out of nothing nor can it disappear, but this tautology tells us nothing about why the accumulation of triglycerides is happening. The tautology (in its correct form) is useless. The false sense of utility provided by the Energy Balance Theory comes from a deceitful transformation of the useless tautology: the trick is that the boundary for the application of the First Law of Thermodynamics is unjustifiably considered to be the whole body’s boundary, instead of the correct boundary, which is the adipose tissue’s boundary. Understanding this deception is crucial: if you want to apply the First Law of Thermodynamics, you must have a clearly defined physical boundary in its use. The Energy Balance Theory violates that principle and that fact makes this theory a hoax.

A thermodynamic system is that part of the world to which we are directing our attention. Everything that is not a part of the system constitutes the surroundings. The system and surroundings are separated by a boundary.

Internal energy is the totality of all forms of kinetic and potential energy of the system

When the “Calories In” and “Calories Out” terms are used, the physical boundary is the whole body’s boundary. This is mandatory. And, therefore, the totality of all forms of energy in the body have always to be taken into account. It is unjustifiable and deceitful to only consider the energy stored in a specific tissue (e.g. the accumulation of triglycerides in the adipocytes).

Calories In = Calories Out + Change in FAT DEPOSITS

Calories In = Calories Out + Change in ALL ENERGY STORES

Any energy that’s left over after the body has used what it needs is stored as body fat (source)

That is a theory that doesn’t derive from physics’ laws.

The faux causality problem

Moreover, the Energy Balance Theory relies on an unfounded attribution of causality. It is easy to understand this point, just by comparison with any other growth in a biological system. What does the Energy Balance Theory tell us about conditions such as fatty liver, muscle hypertrophy, giantism or a tumor’s growth? What does it tell us about how anabolic steroids work? All of those situations represent the growth of tissues inside of the body, and therefore they represent energy accumulation in one or several tissues, just as obesity does.

Fatty Liver

Fat accumulates in the liver, therefore

it is an incontrovertible fact of physics that fatty liver happens when calorie intake exceeds expenditure […] the laws of physics ensure that any person will reverse its fatty liver if calorie intake is reduced sufficiently

it is an incontrovertible fact of physics that weight increases when calorie intake exceeds expenditure […] the laws of physics ensure that any obese person will lose weight if calorie intake is reduced sufficiently


Your body can’t grow unless you eat more than you expend:

An imbalance between energy intake and energy expenditure is the primary etiology for giantism.

An imbalance between energy intake and energy expenditure is the primary etiology for excess weight gain.

Muscle mass

Muscle tissue can’t grow unless there is a caloric inbalance:

Muscle hypertrophy is defined as a state of increased muscle mass resulting from chronic nutrient excess, where energy intake significantly exceeds energy expenditure

Obesity is defined as a state of increased adiposity resulting from chronic nutrient excess, where energy intake significantly exceeds energy expenditure


A tumor can’t grow unless more energy comes in than gets out:

A key determinant of a tumor’s growth is the balance between ingested calories and the body’s basal energy expenditure. The tumor’s growth therefore results when small positive energy balances accumulate over a long period of time

A key determinant of obesity is the balance between ingested calories and the body’s basal energy expenditure. Obesity therefore results when small positive energy balances accumulate over a long period of time

Anabolic steroids

Do anabolic steroids increase your muscle mass by making you hungry or sedentary?

if anabolic steroids don’t increase energy intake […], and don’t decrease energy expenditure, then how exactly are they supposed to cause energy accumulation in the body as fat? There is no energy fairy

if insulin doesn’t increase energy intake [… ], and doesn’t decrease energy expenditure, then how exactly is it supposed to cause energy accumulation in the body as fat? There is no energy fairy

Your energy expenditure is not a controllable input of the system

The Energy Balance Theory hoax is supported with rethorical fallacies where the energy expenditure is alluded as if it were a controllable input of the equation. It is not. If both energy intake and energy expenditure are considered inputs of the system, and if the decepcion explained above is used (i.e. considering only the energy stored in a specific tissue), a false impression of causality is created:

When calorie expenditure decreases and calorie intake increases, the energy balance equation leaves only one possible outcome: fat gain (source)

When calorie expenditure decreases and calorie intake increases, the energy balance equation leaves only one possible outcome: fatty liver or muscle hypertrophy or giantism or a tumor’s growth or you are pregnant and the fetus grows

As explained above, to assume a result for an output (“calorie expenditure decreases”) is cheating. It is not an input we can control.

When calorie intake increases, in the case where the calorie expenditure decreases the energy balance equation leaves only one possible outcome: fatty liver or muscle hypertrophy or giantism or a tumor’s growth

The energy balance equation can NEVER be used to predict the response from a living tissue to a stimulus, because that law has nothing to do with biology. Its use related to the study of obesity is based on rethorical fallacies and it is, therefore, unwarranted.

Does this mean that the First Law of Thermodynamics is not valid in a biological system?

That idea is not correct: the First Law of Thermodynamics is always fulfilled, and, therefore, it is also fulfilled in biological systems. It is the Energy Balance Theory what is a fraud, because it is both a misapplication and a misinterpretation of what the First Law of Thermodynamics says.

The pseudoscience is the pretension that the Energy Balance Theory is rightfully derived from the First Law of Thermodynamics and that, therefore, it must be used to deduce causes and solutions for obesity. The Energy Balance Theory is a hoax and it can’t be used for that purpose, just as it is clearly inappropriate to deduce how to cure your fatty liver, how to increase your muscle mass or how to treat a kid that suffers from giantism. Obesity is not a special condition.

Ultimately, obesity reflects energy imbalance, so the major areas for intervention relate to dietary intake and energy expenditure, for which the main modifiable component is physical activity (source)

Giantism also reflects energy imbalance, right? What are the major areas for intervention in that case? A tumor’s growth also reflects energy imbalance, right? What are the major areas for intervention in that case?

Further reading:

The Minnesota Starvation Study

I’m going over some aspects of The Minnesota Starvation Study, an experiment that has been commented previously in this blog (see,see,see).

“The Minnesota Starvation Study”

The objective of the experiment was to study the recovery phase from a malnutrition condition. In order to do so, first weight loss was induced by caloric restriction and physical exercise. The duration of this first phase was 6 months. After those 6 months, the researchers tested different options in the weight recovery phase.

According to the researchers, the rate of weight loss in the first phase approached zero after 24 weeks (see):

The “ideal” relation between body weight and the course of semi-starvation was believed to be that in which the rate of weight loss would change at constant rate to reach zero change at the end of 24 weeks

Mathematically, the general curve required for weight versus time is represented by a parabola with vertical axis and zero slope at 24 weeks.

Note that the researchers tell us that the body weight evolved in such a way that at week #24 there was no weight loss: “zero change”, “zero slope”.

In the picture below we can see the evolution of the body weight of the participants (white dots) and the energy intake during that period (black dots):


The important fact here is the participants always followed a hypocaloric diet and they stopped losing weight. They went from consuming 3150 kcal/day at the baseline to consuming about 1750 kcal/day. Taking into account only the energy intake, they applied a caloric restriction of around 1400 kcal/day:

It must be noted that the present subjects changed from a control average of 3150 Cal. to a semi-starvation average of 1755 Cal.; this represents a potential deficit of 1395 Cal. per day.

After allowing for all individual adjustments in the diet, the average individual daily intakes averaged, for successive months, 1) 1834, 2) 1833, 3) 1766, 4) 1661, 5) 1694, 6) 1764 Calories.

In short, they are living in a facility, their intake is absolutely controlled, they are eating much fewer calories than they used to, and they are also doing physical exercise (therefore, their enegy expenditure is supposed to be high) (see),

The participants were expected to walk 22 mi (35.4 km)/wk and expend 3009 kcal (12552 kJ)/d.

But after 6 months of caloric restriction, although they still have body fat they could lose, they are not losing any more weight. I want to insist on this: they are “eating a lot less” and they are not losing weight.

As I said above, the official goal of the experiment was to analyse the best way to recover from a malnutrition condition. From 6 months (time point S24 in the graph below) onwards, the energy intake was gradually increased. At time point R12, although the participants always had consumed less calories than they used to (red lines in the picture remained always below 100%), they had already recovered almost all the body fat (point marked with arrows on the solid curve) that they had previously lost.


In this study:

  • weight loss reaches a plateau, although the caloric restriction is maintained and there is still body fat that can be lost
  • under caloric restriction conditions, body fat accumulation has been promoted and although the participants never stopped following the calorie-restricted diet, they gradually increased their body fat


When you are “eating less and moving more”, but you reach a plateau, your options are: keep on following the diet and slowly regain the previously lost weight, or you can start consuming a normal amount of food and you will regain the lost weight faster.

Are we obese because of a hungry brain or are we because of the pseudoscience that the “experts” spread?

The energy balance theory

Stephan Guyenet, PhD has written a book titled “The Hungry Brain: Outsmarting the Instincts That Make Us Overeat “. Just having a look at its cover makes it clear that nothing interesting can be expected from inside the book, as this guy is trying to answer a wrong question: he assumes that the cause of obesity is that we overeat.

A couple of excerpts from the book:

Three independent methods suggest that our calorie intake increased substantially over the course of the obesity epidemic, and this increase is sufficient to account for the weight we gained. Simply stated, we gained weight because we ate more.

When you eat more calories than you burn, the excess calories are primarily shunted into your adipose tissue. Your adiposity, or body fatness, increases. It really is as simple as that

Any energy that’s left over after the body has used what it needs is stored as body fat

When calorie expenditure decreases and calorie intake increases, the energy balance equation leaves only one possible outcome: fat gain. We gained fat as we ate more calories than we needed to remain lean, given our physical activity level. In other words, we overate.

Quackery and pseudoscience

Two sentences from Guyenet’s book are perfect as an illustration of how the energy balance pseudoscience is built:

When you eat more calories than you burn, the excess calories are primarily shunted into your adipose tissue. Your adiposity, or body fatness, increases. It really is as simple as that

Any energy that’s left over after the body has used what it needs is stored as body fat

Is actually that the way our body works? First our body uses the energy it needs, and then what’s left is stored as body fat? Is that what our knowledge of the human body’s physiology says that happens? I’d like to see the scientific evidence that supports Guyenet’s claims, because I think it is absolutely UNTRUE that our body works the way he declares. Guyenet’s ideas are not science, they are quackery.

What are the tricks here?

    1. the sophistry makes energy expenditure seem like an input in the “human body” system. And once two terms of the energy balance (i.e. expenditure and intake) are fraudulently presented as inputs, then the energy balance equation is used to deduce that the the third one (energy stored as body fat) is forced to change. But the caloric intake is, actually, the only input in the “energy balance” model: energy expenditure and energy accumulation are outputs/results/consequences, not inputs/variables under our control. They deduct what is cause and what is effect from a mathematical equation when causality can only be inferred from the knowledge of how this particular system works.
    2. without any possible justification, they use the term “body fat” in the energy balance equation, instead of “energy accumulation”. The result of this is that two terms of the energy balance equation are related to the human body as a whole, but the third one (and also the conclusions) are related to a specific tissue. As I said before: unjustifiable.
    3. they perform a one-dimensional problem analysis, one that misleadingly only takes into account the “energy” variable and, logically, this approach is a blind alley in which the only conclusion that can be reached is to identify the calories as cause or solution for our obesity problem.

Moreover, the data that Guyenet is using is epidemiological, i.e. statistical data from a population. These data aren’t from a controlled experiment’s output. In this case, not even the caloric intake is necessarily an input, a cause: a priori it is only an effect, an observed symptom. Nobody here has carried out a controlled experiment in which the caloric intake has been increased: we are observing that the caloric intake has increased in the last decades, because of an unknown cause. There is no rational basis supporting Guyenet’s claims, which are the idea that two of the terms of the energy balance equation have changed and then, as a consequence, the third one has been forced to change.

An inappropriate food composition (i.e. the presence of sugars, grain flours, added chemicals, etc.) could have simultaneously induced fat accumulation —-per se, independently of the calories consumed—, an increase in the caloric intake (which in turn aggravates the body fat accumulation) and a reduction of the physical activity levels. The laws of thermodynamics can’t say what is cause and what is effect, nor do they impose a relevant role for energy, neither as a cause nor as a solution to the problem of obesity. The idea that “calories count” is not derived from the thermodynamics laws, and therefore it needs to be proved. I believe it is really significative that when evidence is presented to defend this theory, it is always false.

Although I have written repeatedly about all these sophisms, there is one of them that I consider critical:

from a tautology (i.e. saying the same in a different way) it is inferred that gaining or losing weight are energy balance issues, and that talking about calories is unavoidable.

“If you eat more calories than you burn, you will gain weight”


The best way to explain the deception is, probably, to apply the same reasoning to a different tissue, e.g. muscle mass:

the laws of physics tell us that muscle mass can’t get bigger unless you eat more than you spend, so the increase in muscle mass happens as a result of a caloric intake that is excessive for your energy needs

You know it is wrong. You know that there is a “trick” in the reasoning. You know that the laws of physics don’t say that the muscle mass increases because you eat too much and move too little, and nobody can convince you of that, no matter how skilled they are playing with words. You understand that, when talking about the muscle tissue, it is absolutely stupid to use the energy balance theory to infer the cause of the growth. Once you realize that facts, nobody will ever convince you that using the laws of physics is a must when talking about the adipose tissue.

If you consume more calories than you burn, will your muscles grow?

What is wrong with the above sentence? This is not a rhetorical question: it is an important one. Can you explain the fallacy?

The carrot, the stick and the string

In one of my favourite blog posts, ““, I use the analogy of a man attached to a carrot by means of a stick and a string (see image below). What I try to to illustrate with the analogy is how solutions for a problem derived from inviolable laws of physics, can be undeniably stupid. As we will see next, a key in the fallacy is assuming a value for a parameter that is not actually under our control.


Referred to the picture above, are the following statements true or false?

If you run faster than the carrot, you’ll reach it.

If you run slower than the carrot, it will eventually disappear from your sight.

Reaching the carrot is about managing your speed relative to the carrot’s speed. Creating a speed surplus is the way to reach it, while a speed deficit will make it move away from you.

Disassembling the stick that links you to the carrot is useless, because unless your speed is greater that the carrot’s you won’t reach it.

Are you still not persuaded that speed is the key to solve the problem?

all you need is to know is the carrot’s speed and then move faster than it. Let’s say that the carrot is moving at 1 km/h. In this case, you only need to move a little faster, for example at 2 km/h, and I can guarantee that you’ll reach the carrot. It really is as simple as that.

Do you disagree with this? May be you think that it is possible to reach the carrot without being faster than it is? I’m sorry to break this to you, but that would violate the laws of physics and you can’t do that.

Is it true that if you run faster than the carrot you’re going to catch it? Yes, it is, but it is a sophism , because this solution is only correct in appearance, since it is unrelated to the specifics of the problem. Any reference made to the carrot’s speed should be making clear that this magnitude is an observed output, instead of giving the impression that it is an input with a specific value or that we can force a positive or negative difference relative to another parameter.

According to logic, what is the relationship between the man’s speed and his distance to the carrot? Does logic say that managing his speed is the way to reduce that distance? Do the laws of physics tell us that any solution that works does so simply because it helps us increase our speed?

If the laws of physics say always exactly the same thing, whether there is or there isn’t a stick that links you to the carrot, can these laws be useful in any way to solve the problem?

The laws of thermodynamics are exactly the same regardless of the physiological mechanism used by an adipocyte to grow! What on earth made us believe that these laws can be useful for understanding or curing obesity? Nobody uses them with any other growth of a tissue. Isn’t that fishy?


We are nothing else than arrogant morons. If we ask a child for help on how to reach the carrot, he/she will not say that you have to create a speed surplus. Moreover, the “speed” concept won’t even cross his/her mind. And he/she will solve the problem. The fact that a law of physics is inviolable, doesn’t mean that that law is necessary, nor useful nor relevant to solve a problem. In my opinion, the people that defend the use of the laws of thermodynamics in nutrition are themselves the problem and will never be the part of the solution.

If you consume 2000 kcal/day and your expenditure is 1950 kcal/day, you will gain weight. If you have that same energy expenditure and you consume only 1900 kcal/day, you will lose weight.

Did we gain weight because we consumed more calories than we expended? Can you tell now how, from a tautology that tells us nothing useful, has the energy balance pseudoscience been built?

Further reading:

Sugar-sweetened beverages and obesity

DAILY calories from sugar-sweetened beverages among U.S. adults (1980-2010):

imagen_0462 (source,source)

CUMULATIVE TOTAL increment in the percentage of obese adults (orange stars) versus CUMULATIVE TOTAL calories from sugar-sweetened beverages (blue line; numerical data not shown in the figure):

Are these data consistent with an important effect of sugar-sweetened beverages on body weight? Do they suggest, on the contrary, that sugar-sweetened beverages are highly unlikely to be an important cause of obesity?

Further reading: