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Will Brink's Unified Theory of Nutrition

Will Brink attempts to unify seemingly incompatible or opposing views regarding nutrition, namely, what is probably the longest-running debate in the nutritional sciences: calories vs macronutrients.

When people hear the term Unified Theory, sometimes 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 is how important unified theories can be. However, unified theories do not 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 stated 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 macronutrients.

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 about where the calories come from (e.g. carbs, fats, and proteins), which dictates weight loss or weight gain. Meaning, they feel that the old school's "calorie is a calorie" mantra is wrong. They, too, come to this conclusion using various lines of evidence.

For decades, this has been an ongoing debate between people in the field of nutrition, biology, physiology, and many other disciplines. The result 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 understanding any unified theory:

  • A good unified theory is simple, concise, and understandable even to laypeople. However, underneath, or behind that theory, is often a great deal of information that can take up many 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.
  • Some theorists often propose a unified theory before it can even be proven or fully supported by physical evidence. Over time, different lines of evidence, whether mathematical, physical, etc., support the theory and thus solidify that theory as correct, or continued lines of evidence show the view needs to be revised or 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 for 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. four calories per gram and fat approximately nine calories per gram, and the source of those calories matters not. They base this on the many studies that find 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 consider 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 consider that even within a macronutrient, 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 macronutrient ratios with identical calorie intakes have other effects on body composition, cholesterol levels, oxidative stress, etc.

Translated, not only is the mantra "a calorie is a calorie" proven to be false, "all fats are created equal" or "protein is protein" is also incorrect. For example, we now know different fats (e.g. fish oils vs saturated fats) have vastly different effects on metabolism and health in general, as we now know different carbohydrates have their effects (e.g. high GI vs low GI), as we know different proteins can have unique effects.

The "calories do not matter" school of thought

This school of thought will typically tell you that calories do not matter if you eat large amounts of some particular macronutrient in their magic ratios. For example, followers of ketogenic style diets that consist of high-fat intakes and very low carbohydrate intakes (i.e. Atkins, etc.) often maintain calories do not matter in such a diet. often maintain calories do not matter in such a diet. Others claim that calories do not count if you eat very high protein and low fat and carbohydrate intakes. Like the old school, this school fails to consider the effects such diets have on various pathways and ignore the simple realities of human physiology, not to mention the laws of thermodynamics

The reality is, although it is clear different macronutrients in different amounts and ratios have different effects on weight loss, fat loss, and other metabolic effects, calories do matter. They always have, and they always will. The data and real-world experience of millions of dieters clearly reflect that reality.

The truth behind such diets is that they are often quite good at suppressing appetite, and thus the person ends up eating fewer calories and losing weight. Also, the weight loss from such diets is often from water vs fat, at least in the first few weeks. That is not to say people cannot experience significant weight loss with some of these diets, but the effect comes from a reduction in calories vs any magical effects often claimed by proponents of such diets.

Weight loss vs fat loss!

This is where we get into the crux of the actual debate and why the two schools of thought are not as far apart from one another as they appear to the untrained eye. What has become abundantly clear from the studies performed and real-world evidence is that to lose weight we need to use more calories than we take in (via reducing calorie intake and or increasing exercise), but we know different diets have different effects on the metabolism, appetite, body composition, and other physiological variables...

Brink's Unified Theory of Nutrition

Thus, this reality has led me to Brink's Unified Theory of Nutrition which states:

"Total calories dictates how much weight a person gains or loses;
macronutrient ratios dictate what a person gains or loses"

This seemingly simple statement allows people to understand the differences between the two schools of thought. For example, studies often find that two groups put on the same calorie intakes. Still, very different ratios of carbs, fats, and proteins will lose different amounts of body fat and or lean body mass (i.e. muscle, bone, etc.).

Some studies find that people on a higher protein lower carb diet lose approximately the same weight as others on a high carb lower protein diet, but the group on the higher protein diet lost essential fat and less lean body mass (muscle). Or, some studies use the same calorie intakes, but different macronutrient intakes often find the higher protein diet may lose less actual weight than the higher carb lower protein diets. Still, the fat loss is higher in the higher protein low carb diets. This effect has also been seen in some studies that compared high fat/low carb vs high carb/low-fat diets. As one might expect, the result is usually amplified if exercise is involved.

Of course, these effects are not found universally in all studies that examine the issue. Still, the bulk of the data is clear: diets containing different macronutrient ratios do have different effects on human physiology even when calorie intakes are identical (see references 1 to 11 inclusive). Or, as the authors of one recent study that looked at the issue concluded:

"Diets with identical energy contents can have different effects on leptin concentrations, energy expenditure, voluntary food intake, and nitrogen balance, suggesting that the physiologic adaptations to energy restriction can be modified by dietary composition." (Agus et al. 2000)[12]

Many studies confirm that the actual ratio of carbs, fats, and proteins in a given diet can affect what is lost (i.e. fat, muscle, bone, and water) and that total calorie has the most significant effect on how much total weight is lost. Are you starting to see how my unified nutrition theory combines the "calorie is a calorie" school with the "calories do not matter" school to help people make decisions about nutrition?

Knowing this, it becomes much easier for people to understand the seemingly conflicting diet and nutrition advice out there (of course this does not account for the downright unscientific and dangerous nutrition advice people are subjected to via bad books, TV, the 'net, and well-meaning friends, but that is another article altogether).

  • Knowing the above information and keeping the Unified Theory of Nutrition in mind leads us to some important and potentially valuable conclusions
  • An optimal diet designed to make a person lose fat and retain as much LBM as possible is not the same as a diet designed to lose weight
  • A nutrition program designed to create fat loss is not a reduced calorie version of a nutrition program designed to gain weight and vice versa
  • Diets need to be designed with fat loss, NOT just weight loss, as the goal, but total calories cannot be ignored.

This is why the diets I design for people-or write about-for gaining or losing weight are not higher or lower calorie versions of the same diet. In short: the diet plans I design for gaining LBM start with total calories and build macronutrient ratios into the number of calories required.

However, diets designed for fat loss (vs weight loss!) start with the correct macronutrient ratios that depend on variables such as the amount of LBM the person carries vs. body fat percent, activity levels, etc., and figure out calories based on the proper macronutrient ratios to achieve fat loss with a minimum loss of LBM. The actual ratio of macronutrients can be quite different for both diets and individuals.

Diets that give the same macronutrient ratio to all people (e.g. 40/30/30, or 70,30,10, etc.), regardless of total calories, goals, activity levels, etc., will always be less than optimal. Optimal macronutrient ratios can change with total calories and other variables.

Perhaps most important, the unified theory explains why the focus on weight loss vs fat loss by the vast majority of people, including most medical professionals, and the media, will always fail in the long run to deliver the results people want.

Finally, the Universal Theory makes it clear that the optimal diet for losing fat, or gaining muscle, or whatever the goal, must account not only for total calories but macronutrient ratios that optimize metabolic effects and answer the questions: what effects will this diet have on appetite? What effects will this diet have on metabolic rate? What effects will this diet have on hormones, which may improve or impede my goals? What effects will this diet have on (fill in the blank)?

Asking, "how much weight will I lose?" is the wrong question, leading to the wrong answer. To get the optimal effects from your next diet, you must ask the right questions to get meaningful answers, whether looking to gain weight or lose it.

Asking the right questions will also help you avoid the pitfalls of unscientific, poorly thought out diets that make promises they cannot keep and go against what we know about human physiology and the very laws of physics!

There are, of course, many additional questions that can be asked and points that can be raised as it applies to the above, but those are some of the key issues that come to mind. The bottom line here is, if the diet you are following to either gain or loss weight does not address those issues and or questions, then you can count on being among the millions of disappointed people who do not receive the optimal results they had hoped for and have made yet another nutrition "guru" laugh to the bank at your expense.

Any diet that claims calories do not matter; forget it. Any diet that tells you they have a magic ratio of foods; ignore it. Any diet that says any food source is evil; is a scam. Any diet that tells you it will work for all people all the time no matter the circumstances, throw it out or give it to someone you do not like!


  1. FARNSWORTH, E. et al. (2003) Effect of a high-protein, energy-restricted diet on body composition, glycemic control, and lipid concentrations in overweight and obese hyperinsulinemic men and women. Am J Clin Nutr., 78 (1), p. 31-39.
  2. BABA, N.H. et al. (1999) High protein vs high carbohydrate hypoenergetic diet for the treatment of obese hyperinsulinemic subjects. Int J Obes Relat Metab Disord., 23 (11), p. 1202-1206.
  3. PARKER, B. et al. (2002) Effect of a high-protein, high-monounsaturated fat weight loss diet on glycemic control and lipid levels in type 2 diabetes. Diabetes Care., 25 (3), p. 425-430.
  4. SKOV, A.R. et al. (1999) Randomized trial on protein vs carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obes Relat Metab Disord., 23 (5), p. 528-536.
  5. PIATTI, P.M. et al. (1994) Hypocaloric high-protein diet improves glucose oxidation and spares lean body mass: comparison to hypocaloric high-carbohydrate diet. Metabolism. 43 (12), p. 1481-1487.
  6. LAYMAN, D.K. et al. (2003) A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women. J Nutr. 133 (2), p. 411-417.
  7. GOLAY, A. et al. (1996) Weight-loss with low or high carbohydrate diet? Int J Obes Relat Metab Disord. 20 (12), p. 1067-1072.
  8. MECKLING, K.A. et al. (2002) Effects of a hypocaloric, low-carbohydrate diet on weight loss, blood lipids, blood pressure, glucose tolerance, and body composition in free-living overweight women. Can J Physiol Pharmacol. 80 (11), p. 1095-1105.
  9. BORKMAN, M. et al. (1991) Comparison of the effects on insulin sensitivity of high carbohydrate and high fat diets in normal subjects. J Clin Endocrinol Metab. 72 (2), p. 432-437.
  10. BREHAM, B.J. et al. (2003) A randomized trial comparing a very low carbohydrate diet and a calorie-restricted low fat diet on body weight and cardiovascular risk factors in healthy women. J Clin Endocrinol Metab. 88 (4), p. 1617-1623.
  11. GARROW, J.S. et al. (1981) The effect of meal frequency and protein concentration on the composition of the weight lost by obese subjects. Br J Nutr. 45 (1), p. 5-15.
  12. AGUS, M.S. et al. (2000) Dietary composition and physiologic adaptations to energy restriction. Am J Clin Nutr. 71 (4), p. 901-907.

Page Reference

If you quote information from this page in your work, then the reference for this page is:

  • BRINK, W. (2008) Will Brink's Unified Theory of Nutrition [WWW] Available from: [Accessed

About the Author

Will Brink has over 15 years of experience as a respected author, columnist, and consultant, in the supplement, fitness, bodybuilding, and weight loss industry and has been extensively published. Will graduated from Harvard University with a concentration in the natural sciences and is a consultant to major supplement, dairy, and pharmaceutical companies.