Retrospective #6: “Energy In = Energy Out”: An Alternative Interpretation

The one universally held truth in the common understanding of human metabolism is the Energy Equation: “Energy In = Energy Out.” It is generally endorsed by most doctors, even some medical researchers, and universally by the popular press and the public at large. Why? Because it is so easy to understand.  It is, simply, “common sense.”

It also gains gravitas by its association with one of the basic laws of science, the First Law of Thermodynamics, as described in Wikipedia: “The total energy of an isolated system is constant. It can be transformed from one form to another, but it can neither be created nor destroyed.” Now, who’s gonna argue with “The First Law”! You’d have to be some kind of kook to even try, and you would be laughed at, all the way to (and in) the grave (viz: Atkins).

Okay. I’ll try. I get the courage because Gary Taubes, in his seminal opus “Good Calories – Bad Calories,” introduced in the last column, has convinced me. So, with apologies to Taubes for any errors in my understanding, I will try to recapitulate his explanation here to help convey an “Alternative” Interpretation of the immutable First Law of Thermodynamics, as it applies to the “Energy In = Energy Out” formulation for “energy balance,” or Homeostasis.

The problem with the conventional interpretation of the “Energy In = Energy Out” formula is that it measures “Energy in” in the wrong place, i. e., from outside the body, as something done to the body. Thus, the common-sense, universally believed understanding is as follows: Energy In (food eaten) = Energy Out (basal metabolism plus the added energy expenditure of activities, including exercise). Therefore, to lose weight (“improve” the energy balance) you must decrease calories (i.e., reduce “Energy in”) and/or exercise more (increase energy expended, i.e., “Energy out”). Sound familiar? Of course! It’s the ubiquitous “diet and exercise” prescription dished out by the medical and public health establishment. But this interpretation of how the Energy Equation works, with respect to where “Energy in” is measured, is fundamentally wrong, according to Gary Taubes, et. alia, Including now… me.

According to Taubes, the operative place to observe and measure Homeostasis (how the body itself modifies energy intake and expenditure to maintain a balanced state), is in the blood stream. The sources of all energy to the blood stream – the “Energy in” or left side of the equation – are basically three-fold: 1) energy from food eaten and digested, 2) energy stored in the liver and muscles, and 3) energy from our fat cells (adipose tissue aka triglyceride molecules), if allowed to break down when needed for energy. Take note in particular of this last source on the “Energy in” side of the equation, the very important “if allowed.” There’s a conditional aspect to it.

This 3^rd source of “Energy in” – our body fat – is the critical difference. With it you can 1) avoid the starvation aspect of conventional reduced calorie, balanced diet programs, 2) prevent that always hungry feeling, including cravings and the need to snack between meals and 3) give your body all the energy it needs, avoiding that drained, weak feeling. It is also an easy way to lose weight and keep it off, as long and so long as you stay with it.

The body itself balances the energy equation. That energy can include body fat, if allowed, through complex signals from various hormones, putting on the right side of the equation however much energy it needs. It will meet the needs of our basal metabolism plus whatever our activity level requires, if it can get access to that body fat. It will use the first two sources on the left side of the equation (1) food eaten and 2) energy stored in the liver and muscles), and then, if it is “allowed,” energy from the 3rd source, our body’s own fat cells. This last energy source, however, is, as we said, conditional, and it is critical to understand how the body can get access to it.

Once understood, and with knowing the Macronutrient composition of the foods we eat and the key role of the hormone insulin, we can learn how to use all three sources on the “Energy In” side of the equation.

Next, we’ll discuss what “if allowed” and “access” means, that is, how the mechanism works. It worked for me; it will work for you too. After all, it’s the frickin’ First Law of Thermodynamics, as correctly understood and applied.