The Current View of Energy Balance

Let’s start out with a few pictures illustrating the current view of energy balance, or, at least, how most people view the relationship between "calories in" and "calories out."

The first image below represents how most people perceive the energy balance equation during weight maintenance. As the diagram represents, when "calories in" are equivalent to "calories out," body mass should remain constant.

The next image below represents the conventional view of the energy balance equation during weight gain. As the diagram represents, when "calories in" exceed "calories out" body mass should be gained.

The next image below represents the conventional view of the energy balance equation during weight loss. As the diagram represents, when "calories out" exceed "calories in," body mass should be lost.

Now, in looking at these pictures it’s important to understand exactly what they represent. These pictures represent a scientific model, or in other words, a mental picture, or idealization, based on physical concepts and aesthetic notions that account for what scientists see regarding a particular phenomenon. And not only does a scientific model, as described above, explain a particular phenomenon, it allows scientists to predict a future course for the phenomenon in question.

Therefore, if the energy balance model above (or as we understand it, based on the pictures) can consistently explain body composition changes seen in those altering their exercise and nutritional habits, as well as predict how any specific change in either variable will impact body composition in the future, it’s a valid model. If not, it’s invalid (incomplete, misunderstood, or completely wrong).

From that perspective, let’s take a few case studies of mine and see if the model above holds up under the explanatory and predictive scrutiny necessary for a scientific model to be valid.

Three Strikes and You’re Out
In order to support my contention that the above-mentioned model of energy balance (or as we understand it, based on the pictures) is inadequate; here are 3 case studies for your examination.

*Case Study #1:
National Level Cross Country Skier; Female - 20y

Client Information from September 2002:
5’6" ; 160lb ; 22% fat
(125lb lean, 35lbs fat)

Exercise Expenditure:
~1200kcal/day

Energy Intake:
~2500kcal/day
15% protein
65% carbohydrate
20% fat

Client Information from December 2002:
5’6" ; 135lb ; 9% fat
(123lb lean, 12lbs fat)

Exercise Expenditure:
~1200kcal/day

Energy Intake:
~4000kcal/day
35% protein
40% carbohydrate
25% fat

Net result ' 12 weeks:
25lbs lost; -23lb fat; -2lbs lean

*Note that in case study #1, we increased energy intake by a whopping 1500 per day while energy expenditure remained the same. Since the athlete was weight stable in September'prior to hiring me'you might have expected her to have gained weight during our 12 week program. However, as you can see, she lost 25lbs (while preserving most of her muscle mass). Since the energy balance model above, as it appears, can’t explain this very interesting result, that’s one strike.

*Case Study #2:
Beginner Weight Lifter; Male ' 23y

Client Information from August 2003:
5’6" ; 180lb ; 30% fat
(126lb lean, 54lbs fat)

Exercise Expenditure:
~200kcal/day

Energy Intake:
~1700kcal/day
21% protein
57% carbohydrate
22% fat

Client Information from October 2003:
5’6" ; 173lb ; 20% body fat
(138.5lb lean, 34.5lbs fat)

Exercise Expenditure:
~600kcal/day

Energy Intake:
~2200 - 2400kcal/day
35 - 40% protein
30 - 35% carbohydrate
30 - 35% fat

Net result ' 8 weeks:
7lb weight loss; -19.5lb fat, +12.5lb lean

*Notice that in case study #2, we increased energy intake by between 500 and 700 per day while increasing energy expenditure by about 400 per day. Again, since the lifter was weight stable in June, prior to hiring me, you might have expected him to have gained weight or at least remained weight stable during this 8 week program. However, as you can see, he lost 7 lbs. But that’s not the most interesting story. During the 8 weeks, he lost almost 20lbs of fat while gaining almost 13 lbs of lean mass. Since the energy balance model above, as it appears, can’t explain this very interesting result, that’s two strikes.

*Case Study #3:
Mixed Martial Arts Trainer; Male ' 35y

Client Information from June 2004:
5’10" ; 179lb ; 19% fat
(148.6lb lean, 30.4lbs fat)

Exercise Expenditure:
~300kcal/day

Energy Intake:
~1100 - 1500kcal/day
48% protein
25% carbohydrate
27% fat

Client Information from August 2004:
5’10" ; 187lb ; 9% body fat
(170.2lb lean, 16.8lbs fat)

Exercise Expenditure:
~600kcal/day

Energy Intake:
~2400 - 2600kcal/day
26 - 38% protein
28 ' 42% carbohydrate
22 ' 34% fat

Net results ' 8 weeks:
8lb weight gain; -13.6 lb fat, +21.6 lb

*Notice that in case study #3, we increased energy intake by between 1100 and 1300 per day while increasing energy expenditure by only about 300 per day. Again, since the lifter was weight stable in June, prior to hiring me, you might have expected him to have experienced a large gain in mass, both significant muscle and fat gains. However, as you can see, he gained 8 total lbs, having lost almost 14lbs of fat while gaining nearly 22lbs of lean mass. While the energy balance equation might have predicted weight gain, it’s unlikely that it would have predicted the radical shift in body composition seen in this individual. Yet another strike against the current view of energy balance, as it appears.

Simplicity and Energy Balance

After looking at the case studies above, you might be wondering where the classic view went wrong. (You also might be wondering what these individuals were on in order to progress so quickly'well, actually, not one of them took steroids or any nutritional supplements more powerful than Low-Carb Grow! Surge, and fish oil).

Although scientists are still trying to work out what types of metabolic "uncoupling" are going on in order to produce results like those results above, it’s my belief that the current view of energy balance (depicted in the slides above) is just too simple to offer consistent explanatory and predictive power in the realm of body composition change. Below are the three main reasons I believe this to be true:

1. Calorie restriction or overfeeding (in the absence of other metabolic intervention like drugs, supplements, or intense exercise) is likely to produce equal losses is lean body mass and fat mass (w/restriction) or equal gains in lean body mass and fat mass (w/overfeeding). And even if these gains or losses aren’t necessarily equal, they still are in such a proportion that while body mass may be affected, individuals will only likely end up smaller or larger versions of the same shape. I call this the "body shape status quo".(1)

2. Most people assume too much simplicity by associating energy intake with calorie intake alone, and energy expenditure with exercise activity alone. This simplistic view can lead to false assumptions about what causes weight gain and weight loss.(2) Both sides of the equation are much more complex and it’s these interrelationships that are important to physique mastery.

3. Most people treat the energy intake and energy expenditure sides of the equation as independent. As a result, even if we could avoid reason #2 (the problem of simplicity) by matching energy intake against all the known forms of work that the body does in utilizing energy,

"…Obesity can arise in the absence of calorie over consumption. In addition, opposite models can show how obesity can be prevented by increasing expenditure to waste energy and stabilize body weight when challenged by hyperphagia (over consumption)". (3)

Factors Affecting Energy Balance

Now, when I say that most people assume too much simplicity by associating energy intake with calorie intake alone, and energy expenditure with exercise activity alone, I’m not shaking my finger at them. Obviously, of the factors playing into energy balance, these are the most readily modifiable. But, assuming they are the only factors playing into energy balance is what gets people into trouble.

In the diagram below, I’ve outlined all the factors that we currently know to impact both the energy intake and energy expenditure sides of the energy balance equation.

Notice one thing, though. I don’t mention hormones here. The reason: hormones don’t impact energy expenditure directly. Rather, they signal a change in one of the factors listed on the energy expenditure side of the equation (or they lead to an increased appetite, thus are two steps removed from affecting the energy intake side of the equation).

Obviously, this relationship is much more complex than most people make it out to be. Sure, on the energy intake side of the equation, things are fairly simple. The "calories in" are mostly affected by the efficiency of digestion (90-95% of energy in). And we can control this side by volitionally choosing how much we stuff in our mouths.

However, on the energy expenditure side, we’ve got three major "destinations" for our ingested energy; work, heat and storage. And all the energy coming in goes to one of those three destinations. From this perspective, although it seems a bit counterintuitive, we’re actually always in "energy balance" regardless of whether we’re gaining or losing weight. The energy taken in is always balanced by the energy going toward work, heat and storage.

The interesting part is that during periods of over- or under feeding, the amount of energy in can influence most of the factors on the energy out side.

Relationships Between Energy In and Energy Out

In order to add another touch of complexity to the discussion, as discussed above, most people treat the two sides of the energy balance equation as independent. They’re not. But don’t just take my word for it:

"The regulatory systems (of the body) control both energy input and output so that for a given steady state, compensatory changes on the input side are made if expenditure is challenged, or on the output side (expenditure or efficiency) if intake is challenged…Realizing human obesity is caused by the interaction of an obesigenic environment with a large number of susceptibility genes, successful treatment will require uncoupling of these compensatory mechanisms" (4).

"The critical issue in addressing the problem of alterations in body weight regulation is not intake or expenditure taken separately, but the adjustment of one to the other under ad libitum food intake conditions" (5).

In the end, as these scientists suggest, understanding the relationship between "energy in" and "energy out" requires a more complex energy balance model than the one most people currently picture in their minds. And, as promised above, here’s my take on what this model should look like in order to more accurately reflect what’s going on with energy balance.

Dr. JB’s Energy Balance Model

Let’s walk through this model together.

First, energy is ingested, with 90-95% of it being digested and absorbed. Once this energy reaches the cells, the intake is "sensed" by the body and signals are sent to the brain (and other tissues) to manipulate energy expenditure.

Here’s one way that energy intake is "sensed." (For a more detailed explanation, check out check out Part 1 of my "Hungry Hungry Hormone" article series.)

Based on the signals received, the brain either sends signals back to the body in order to increase hunger and metabolic efficiency while decreasing metabolism (if in a hypocaloric state), or in order to decrease hunger and metabolic efficiency while increasing metabolism (if in a hypercaloric state).

A complete understanding of this model leads us to realize that trying to manipulate total energy intake alone in order to alter body composition lets us down because the energy expenditure side of the equation quickly changes to accommodate intake conditions. And trying to manipulate the energy expenditure side of the equation in order to alter body composition lets us down because the energy intake side of the equation is signaled to change in order to match expenditure conditions. In the end, this entire system is in place to prevent significant deviations from a comfortable body composition homeostasis. However, we all know that body mass and body composition can be altered reliably and homeostasis can be overcome to one degree or another. So, how do we manage to "outsmart" the body?

Well, various strategies can help to "uncouple" the relationships between energy intake and expenditure. I’ve detailed a few of them below.

Energy Uncoupling

Notice that there are two possible "uncoupling points" in this energy balance model.

The first uncoupling point lies in the communication between energy sensing/brain signaling (the lower arrow) and the second lies in the communication between the brain and the body'particularly in the drive to eat and the drive to move (the upper arrow).

Think of what dieters face during those inevitable dieting stalemates that nearly all of us have experienced. Once energy is restricted, appetite is reduced and both exercise and non-exercise energy expenditure is reduced. In order to combat this inevitable metabolic slow-down, a few of the strategies illustrated above can be beneficial.

First, on the energy sensing/signaling end, periodic re-feeding, the use of carbohydrate or carbohydrate/protein drinks during exercise, and upregulation of thyroid function by nutritional supplements designed to provide raw materials for thyroid hormone manufacture or to stimulate the conversion of T4 to the more active T3 in the body can help keep the metabolic signal alive.

Secondly, on the brain to body end (the drives to eat and move), although signals are sent to increase food intake and decrease voluntary activity, these can be uncoupled by refusing to eat more in the face of increased hunger.

Also, uncoupling can occur as a result of performing more exercise and non-exercise activity (including using strategies for increasing the cost of each activity ' wearing an X-vest when walking, for example) in an attempt to maintain pre-diet energy expenditure.

If you’re looking for more tips for uncoupling the tight relationship between energy intake and energy expenditure, check out Dr Lonnie Lowery’s Losing Your Energy Balance series at www.t-nation.com

In addition, as most of you know, I believe that alterations in food type (what you eat) and food timing (when you eat) can also uncouple this relationship and improve both weight loss profile and muscle building profile. For more on this, check out my" Lean Eatin’" articles ' Part 1 and 2 ' as well asmy Appetite for Construction column right here at JB.com.

And if after reading these articles, you still don’t buy into the calore is not a calorie argument (which is closely related to the concepts presented in this article), check out this recent scientific paper by Buchholz and Schoeller (6).

Finally, check out my review of my presentation at the 2004 SWIS Symposium for a more complete treatment of how to use the information presented in this article to impact fat loss.

In the end, I hope it’s evident that the traditional picture of energy balance is missing one key facet'the fact that energy intake and expenditure are tightly inter-related. Without understanding this relationship, some erroneous conclusions are regularly drawn by dieters and nutritionists, conclusions that prevent the types of success seen in the case studies discussed in this article. Now that you’re armed with this information, you’ll be better equipped to construct nutrition schedules designed to "outsmart" the body, uncoupling this relationship above, and losing fat (or gaining muscle) while others stagnate.

www.Precision-Nutrition.com