When people hear the term Unified Theory, some times called the Grand Unified Theory, or even “Theory of Everything,” they probably think of it in terms of physics, where a Unified Theory, or single theory capable of defining the nature of the interrelationships among nuclear, electromagnetic, and gravitational forces, would reconcile seemingly incompatible aspects of various field theories to create a single comprehensive set of equations.
Such a theory could potentially unlock all the secrets of nature and the universe itself, or as theoretical physicist Michio Katu, puts it “an equation an inch long that would allow us to read the mind of God.” That’s how important unified theories can be. However, unified theories don’t have to deal with such heady topics as physics or the nature of the universe itself, but can be applied to far more mundane topics, in this case nutrition.
Regardless of the topic, a unified theory, as sated above, seeks to explain seemingly incompatible aspects of various theories. In this article I attempt to unify seemingly incompatible or opposing views regarding nutrition, namely, what is probably the longest running debate in the nutritional sciences: calories vs. macro nutrients.
One school, I would say the ‘old school’ of nutrition, maintains weight loss or weight gain is all about calories, and “a calorie is a calorie,” no matter the source (e.g., carbs, fats, or proteins). They base their position on various lines of evidence to come to that conclusion.
The other school, I would call more the ‘new school’ of thought on the issue, would state that gaining or losing weight is really about where the calories come from (e.g., carbs, fats, and proteins), and that dictates weight loss or weight gain. Meaning, they feel, the “calorie Sonavel is a calorie” mantra of the old school is wrong. They too come to this conclusion using various lines of evidence.
This has been an ongoing debate between people in the field of nutrition, biology, physiology, and many other disciplines, for decades. The result of which has led to conflicting advice and a great deal of confusion by the general public, not to mention many medical professionals and other groups.
Before I go any further, two key points that are essential to understand about any unified theory:
A good unified theory is simple, concise, and understandable even to lay people. However, underneath, or behind that theory, is often a great deal of information that can take up many volumes of books. So, for me to outline all the information I have used to come to these conclusions, would take a large book, if not several and is far beyond the scope of this article.
A unified theory is often proposed by some theorist before it can even be proven or fully supported by physical evidence. Over time, different lines of evidence, whether it be mathematical, physical, etc., supports the theory and thus solidifies that theory as being correct, or continued lines of evidence shows the theory needs to be revised or is simply incorrect. I feel there is now more than enough evidence at this point to give a unified theory of nutrition and continuing lines of evidence will continue (with some possible revisions) to solidify the theory as fact.
“A calorie is a calorie”
The old school of nutrition, which often includes most nutritionists, is a calorie is a calorie when it comes to gaining or losing weight. That weight loss or weight gain is strictly a matter of “calories in, calories out.” Translated, if you “burn” more calories than you take in, you will lose weight regardless of the calorie source and if you eat more calories than you burn off each day, you will gain weight, regardless of the calorie source.
This long held and accepted view of nutrition is based on the fact that protein and carbs contain approx 4 calories per gram and fat approximately 9 calories per gram and the source of those calories matters not. They base this on the many studies that finds if one reduces calories by X number each day, weight loss is the result and so it goes if you add X number of calories above what you use each day for gaining weight.
However, the “calories in calories out” mantra fails to take into account modern research that finds that fats, carbs, and proteins have very different effects on the metabolism via countless pathways, such as their effects on hormones (e.g., insulin, leptin, glucagon, etc), effects on hunger and appetite, thermic effects (heat production), effects on uncoupling proteins (UCPs), and 1000 other effects that could be mentioned.
Even worse, this school of thought fails to take into account the fact that even within a macro nutrient, they too can have different effects on metabolism. This school of thought ignores the ever mounting volume of studies that have found diets with different macro nutrient ratios with identical calorie intakes have different effects on body composition, cholesterol levels, oxidative stress, etc.