In the first installment of this excess fat accumulation series, we walked through the pathway that is the build-up of excess fat in adipose tissue. We saw how the unregulated accumulation of fat becomes a health risk as adipose tissue reaches capacity and becomes insulin resistant. This risk manifests as a true health problem as it progresses into metabolic dysfunction – that is, a state of hyperlipidemia, hyperglycemia, systemic inflammation, hyperinsulinemia, and systemic insulin resistance.
In this pathway, we see how this state of metabolic dysfunction arises specifically due to the excess build-up of fat in adipose tissue.
The important questions for us to address now is, Why does this fat build up in excess, and What can we do to prevent (or reverse) it?
With the rest of this series, we will focus on answering these questions – because, if we want to be able to make health-conscious decisions for ourselves, we need to understand how our actions tie into this pathophysiogical pathway, along with how our actions can be mindfully chosen so that we can avoid it (or first reverse it if need be), and instead take our bodies through a life-long journey of good health.
But before diving back into this pathway, we will need to take a brief detour. This detour is necessary because, to be able to effectively answer these questions, we have a bit of work to do straightening out beliefs that you may currently have about weight management.
I can assume that you have arrived here today with preconceived notions about decisions we are supposed to make regarding the weight of your body. I know this because the reigning theory of weight management, calorie balance, is engrained in every nook and cranny of our modern society, and given that you are an individual living in the modern world, there is simply no possibility that you could have made it this far without being taught to focus on the caloric content of food and number of calories burned during exercise in order to balance your weight.
So before going any further, it is necessary to have a brief disucussion on the reigning theory of weight management. In doing so, we will see why it is inadequate, and then, we will see if we can do better.
What is calorie balance?
The reigning theory that attempts to explain excess fat accumulation says that it is because we consume too much energy, while burning too little, that we become fat. It is the abundance of calories entering the system (without a corresponding abundance of energy being burned during exercise) that is the cause of excess fat accumulation.
Then, as the logic goes, to lose weight all we need to do is eat fewer calories and exercise more to burn more calories. This will result in a calorie deficit, which means that there must be a net loss of mass leaving the body (voila! weight loss).
Unfortunately, despite decades spent telling people to simply eat less and exercise more, our obesity rates have not declined, and instead we have a staggering 70% rate of overweight individuals. Instead of adults doing a better job of controlling their energy balance by counting calories, the problem has actually spread, including more adults and a staggering number of children as well.
This is a clear sign that the calorie balance model for weight management needs improvement.
I do want to draw your attention to the word improvement, because here’s the thing – the problem is not that calorie balance as a theory is incorrect; but rather, it is the implementation of the theory as a calorie-counting practice that I believe to be the true problem.
This means that, as we move forward, we must be careful not to ignore calorie balance altogether. Even if calorie balance as weight loss advice by itself has failed us, this is not to say that we should ignore this topic altogether.
For this reason, I want us to take a close look at the theory so that we can see for ourselves what information we can find useful, along with identifying the misconstrued information that we should probably just toss out.
So, what is calorie balance and where did it come from?
As the common wisdom goes, to maintain a body with a healthy weight we simply need to manage how much energy we consume and how much energy we expend. We all know the rule – it’s all about calories in vs. calories out.
This “wisdom” is an extension of the first law of thermodynamics, also known as the conservation of energy. Because energy cannot be created nor destroyed, then the difference in energy that goes into a system and the energy that leaves that system is the change in energy of that system:
Energy in – Energy out = Change in Internal Energy
Which translates to:
Calories in – Calories out = Stored Calories
Because we are generally dealing with the problem of a positive change in mass (or similarly, a positive change in energy), it follows that energy in is greater than energy out:
weight gain: energy in > energy out,
and to reverse this situation:
weight loss: energy in < energy out
Note that this all comes directly from a scientific law. It has been, at least up to this point in history, irrefutable. To create a negative energy balance, the energy into the system must be less than that of the energy leaving the system.
It translates that to lose a large amount of fat mass, the body needs to be put into a calorie deficit, which means that fewer calories must enter the body than are leaving it.
Ans this is why we have been told for decades that we simply need to eat less and exercise more to lose weight. If we can do this, then we will be creating a calorie deficit, forcing the body to shed the excess weight.
Simple, right?
But is it accurate? Is it effective?
As we can clearly see from the fact that the majority of human beings in the modern world struggle to manage their weight in a society that is hyper-focused on calories, I’ll claim that the answer to this question is no; or, at least, that there is significant room for improvement.
To figure out why calorie balance doesn’t always work so well in practice, let’s do two things:
First, let’s look even more closely at the model of calorie balance.
Then, let’s head back to our work with The Reprogrammed Systems Approach and the excess fat accumulation pathway and see how it ties in.
A Gap in Calorie Balance as a Weight Management Practice
We know that the first law of thermodynamics holds true – after all, it is a fundamental law of nature. It is correct to state that energy can’t be created nor destroyed, which means that energy that goes into the body must be accounted for by energy expended or energy stored.
Thus:
calories in – calories out = change in energy stored
However, the problem is that this gets translated to advice on how to cause a change in fat mass by eating fewer calories and/or by exercising more to burn more calories:
calories consumed – calories expended —> change in body weight
Based on this translation, the difference in calories consumed and calories expended will cause a change in weight:
- If calories consumed > calories expended, this will cause a positive change in body weight (weight gain)
- If calories consumed < calories expended, this will cause a negative change in body weight (weight loss)
This interpretation means that a calorie surplus causes weight gain, while a calorie deficit causes weight loss.
And at last, here we have the problem. It’s a subtle one, but can you catch it?
Energy balance tells us that the difference between calories in and calories out is equal to the change in internal energy (and a corresponding change in mass). Yet, this statement of a basic fact, as captured by the equals sign, does not imply any causation – that is, stating that a calorie deficit is equal to weight loss gives us no information as to what is actually driving the loss of fat mass.
All that calorie balance tells us is that if the difference in calories consumed and calories expended is negative, then the system (the body) is in a calorie deficit, from which we can conclude that individual will lose weight. However, we could just as easily state it the other way around: if weight loss occurs, then a calorie deficit will also be present, which means that the individual consumed less energy than was expended.
Note here, there is no causal arrow – a change in one variable does not drive a change in another. They are equal – if one side of the equation happens to be the case, then the other side must also be that same value. If one variable changes, then there must be a change in one (or more) of the other variables such that both sides remain equal.
That is what the equals sign means, and that is all the information we can take away from this fundamental law of nature before we begin making assumptions.
This means that when someone tells you that weight gain is a problem of too many calories and that consuming fewer calories is the solution (or a similar idea with exercise and energy expenditure), you can tell them this:
It is indeed, true, that consuming an excess amount of calories without a corresponding increase in energy expenditure will go hand in hand with weight gain. I know this because the first law of thermodynamics tells me that an increase in energy in without an equivalent change in energy out will result in that positive change in energy stored.
However, this tells me nothing about why this is happening or what I can do to address the problem.
Moreover, to lose weight, there is a need to create a calorie deficit; however, this simple calorie balance model does not tell me what to do to create this deficit.
Energy balance is a useful statement of fact. It tells us what is.
It does not tell us how. If we want to figure out the how, we need to get a little wiser.
We do that by asking more questions. Allow me to present a few that may be useful.
First, I’ll ask them from an energy balance perspective:
- How does a positive energy balance arise across the human body?
- What specific actions lead to the arising of this positive energy balance?
- How does a negative energy balance arise across the human body?
- What specific actions can be taken to create this negative energy balance?
Second, I’ll ask these same questions from a mechanistic perspective:
- How does the human body regulate the flow of energy, both internally (within the sub-sytems supporting the human body) and externally (via behavior), and how does this influence the overall energy balance?
- How do our decisions impact all of this, and how can we use this information to make decisions that lead to a healthy energy balance?
To answer these questions, let us head back to the excess fat accumulation pathway.
Back to The Pathway of Excess Energy Accumulation
In the last installment, we walked through this pathway step-by-step. We saw:
- How energy is stored in adipose tissue as fat.
- Adipose tissue takes in energy (lipids and glucose) from the bloodstream and stores it all as fat (specifically, as triglycerides – three fatty acids bound together by a glycerol molecule).
- Adipose tissue releases this stored fat back into the bloodstream as free fatty acids
- How insulin is the primary regulatory signal governing the bulk flow of energy in and out of adipose tissue
- When insulin is elevated, the bulk flow of energy is driven into storage in adipose tissue
- When insulin levels are low, adipose tissue may release this stored energy back into the bloodstream.
Now let’s look at it again with an energy balance perspective.
Remember energy balance: Energy in – Energy out = Change in Internal Energy
Apply this now to the system that is adipose tissue. First, let’s look at a balanced system:
Now, a system with positive energy balance:
As we saw previously, if this positive state of energy balance is to continue, then adipose tissue will continue to expand and lead to local insulin resistance. From there, if this state continues further, then adipose tissue will reach capacity, leak out excess lipid along with pro-inflammtory cytokines, and the pathway will continue towards systemic insulin resistance and metabolic syndrome.
Here’s another potentially useful question that we can use to address the problem: What factors are influencing the bulk flow of energy to enter into adipose tissue, and also, to limit the amount of lipid leaving adipose tissue?
We already answered these above – here they are again:
- Insulin – the primary signal for energy storage and halted release of fatty acids
- Total energy load – total load of energy flowing through the bloodstream
Combined, we can think about the total amount of energy that is in the bloodstream that can potentially be diverted into storage, along with whether or not insulin is being elevated to send this energy into storage.
This two-factor idea is important because:
- On one hand, it may be the case that insulin is elevated often, and yet so little energy is entering the bloodstream that it really doesn’t lead to too much fat accumulation.
- On the other, it may be the case that lots of energy is entering the bloodstream, and yet insulin is not elevated so that adipose tissue is free to take up and release lipid, with mitochondria being able to utililize this lipid as a fuel source.
Which leads to my following conclusion:
Excess fat accumulation is not simply a problem of hyperinsulinemia, and excess fat accumulation is not simply a problem of too much energy entering the bloodstream. Rather, excess fat accumulation seems to be a problem that involves the combination of hyperinsulinemia and a high load of enregy entering the bloodstream.
Which leads us to yet another question: What impacts insulin levels and total energy load through the bloodstream?
Note that there are multiple levels to this answer. We’ll keep it simple by grouping the answers into two categories: internal (pathways inside the body) and external (the environmental factors that lead to these pathways).
First, let’s look at the internal level:
- Insulin is elevated in response to elevated blood sugar concentration
- the amount of glucose in the bloodstream will largely dictate the amount of insulin produced
- genetic differences in the response to this load of sugar will also dictate how much insulin the pancreas releases; some people may simply be producing more insulin, resulting in more fat storage overall (see reference 1)
- Bulk flow of energy into and out of adipose tissue
- into is fairly straightforward; this is, simply, energy coming in from the intestine
- glucose not immediately used or stored as glycogen will be converted to lipid and stored as fat
- fat coming in from the intestine in an insulin-elevated, pro-energy storage state will go into storage
- out of is is bit more complicated, but we can simplify it in this way:
- low insulin will allow for adipose tissue to naturally release its stored fat
- hormones, such as adrenaline, will signal to adipose tissue to release stored fat as free fatty acids into the bloodstream
- balance of in and out – understand that the energy that is released from storage in adipose tissue and out into the bloodstream may head down various pathways:
- it may make its way to the muscle (or other mitochondria-containing tissue) to be utilized as a fuel source
- or, it may not be used up as a fuel source, and if that’s the case it will (hopefully) make its way back to adipose tissue to be stored safely
- the unhopeful case – that it is stored somewhere else, like inside other organs (ectopic fat storage) where it cannot be safely tucked away
- into is fairly straightforward; this is, simply, energy coming in from the intestine
Second, we can look at the external level and at how our decisions impact the overall flow of energy in and out of the body.
Note that this is, ultimately, the important question that we need to be able to answer if we are going to make healthy decisions regarding our own weight management.
- If we are at a healthy weight and want to continue with this healthy weight for the duration of our lives, then we need to understand how our decisions lead to energy balance over time.
- If we are currently at an unhealthy weight, we need to first be able to understand how to create a negative energy balance, along with how this will change to energy balance once a healthy weight is achieved.
This is the question we will answer in the next installment of this series. As we do so, we will see how specific decisions directly impact this fat accumulation pathway, including insulin levels and total energy load, and of course, overall energy balance within adipose tissue.
For today, I don’t want to leave you hanging about what you can do to avoid this pathophysiologic pathway and the resulting poor health. Fortunately, we already know the simple solution to this entire problem:
- Eat real, whole foods
- food in its natural form generally leads to controlled release of insulin and, often, lower total levels of insulin
- food in its natural form generally leads to controlled amount of energy coming in via:
- satiety and hunger control
- controlled release of energy from the intestine and into the bloodstream
- Move your body regularly and dynamically
- Regular movement will keep energy flux moving through adipose tissue and direct it towards utilization as a fuel source
- Practice a balance of stress and rest
- Stress your body to release energy from storage into the bloodstream
- Stress your body to improve oxidative capacity and thus increase total energy out
- Chill out and relax to help your body re-establish homeostasis
References
- Astley, C. M., Todd, J. N., Salem, R. M., Vedantam, S., & Ebbeling, C. B. (2018). Genetic Evidence That Carbohydrate-Stimulated Insulin Secretion Leads to Obesity. Clinical Chemistry, 000, 1–9. https://doi.org/10.1373/clinchem.2017.280727