Logic Does Not Apply III: A Calorie is a Calorie

TAGS: calorie, kiefer, Nutrition

It’s been awhile since I’ve written an article for elitefts™ and I thought I’d continue the series I began: Logic Does Not Apply. Today, it’s time to attack one of my personal favorites, the saying that a calorie is a calorie.

Without analysis, many people find it hard to imagine that you can take two diets identical in calories, differing in macronutrient makeup — say high carb vs. ultra-low carb — and lose more weight with one than the other. Or better yet, gain weight with one and lose weight with the other. A calorie is a calorie right? Energy-in equals energy-out, or maybe there's some other sciency-phrase that we can pull from our ass to say it's impossible. Ignorance and hubris combine to cause relatively intelligent people to make really stupid comments.

And stupidity propagates myths because people in the United States, even though we rank almost last in all educational standards, rank first in confidence, making us believe that our opinions double as fact. Who would ever think to say, “I don't know,” when they actually don't know? Obviously it’s better to make something up based on hunches, assumptions with a touch of fact sprinkled on top to make it more appetizing. I won't pretend to be immune. I've done it before. It took me a long time to learn to say, “I don't know,” which turns out to be the most valuable thing I ever learned.

Luckily, though, most of the time I do know, which makes me want to smack people when they say, it's impossible to manipulate carbs, protein and fat and lose weight without cutting calories. A calorie is a calorie! It's the first law of thermodynamics. Ha! Take that Mr. Dangerously Hardcore. I said a big sciency-word; I've got my big-boy pants on. Try arguing with that.

Okay, let me give you a tip: don't argue physics with a physicist if you're not one. It's painful for everyone involved, most of all, the physicist. Listening to stupidity hurts. True, the first law of thermodynamics does apply, but it only says that the total energy of the system before and after must be the same. It says nothing about the efficiency of the body in converting that food to energy (either energy for work, or to store as fat), nor does it say if more or less of the energy is wasted if the macronutrient breakdown of the diet changes. In other words, the 1st law says nothing about efficiency. Even if the calories are identical, the 1st law cannot tell us whether eating carbs causes the same reactions in the body as eating fat. It really doesn't say much of anything—except about the ignorance of the person who invoked it as a magical chant.

The Idea

Given two diets identical in calorie count, the two must produce the same weight loss or gain regardless of macronutrient content.

The Logic

By the 1st law of thermodynamics that says energy is neither created or destroyed, must, somehow, say that 100 calories of carbohydrates will produce identical effects as 100 calories of fat — or protein for that matter.

The Reality

The idea that a calorie is a calorie actually violates the laws of physics1-4 and contradicts several well-controlled studies5-14; you can manipulate macronutrients to cause weight-loss even while increasing calories15.

I could go into subjects like Gibb's free energy, non-equilibrium thermodynamics, triaglycerol synthesis, storage and breakdown, violations of the 2nd law of thermodynamics, entropy and so on and so forth, and if you're interested you can check the references, as the subjects are well covered. I am, however going to come from the subject from a simpler point, one that most everyone comprehends and deals with daily: efficiency.

This is where the 2nd law of thermodynamics comes into play. The 1st law may be lame, but the 2nd law allows for the concept of efficiency. At its most basic, efficiency is how much work you can get done based on how much energy is put in. A standard internal combustion engine —l ike the one that runs your car — is roughly 33% efficient, which means that one-third of the energy you put in (the chemical energy stored in the gasoline) does work; the other two-thirds is thrown off as heat.

The body works much the same way. On a standard diet of about 60% carbohydrates, the human body also wastes about two-thirds of the ingested energy as heat. A significant amount is used to help hold our internal temperature steady, but some of the energy is lost in other ways as well. The vast majority of research done on humans and animals dealing with efficiency and wasted heat were done within a narrow range of macronutrient combinations with carbs always leading the way at about 55% of the diet or greater.

But what happens to efficiency when you change the fuel? If you had any sense at all, you’d assume that the efficiency would change—different fuel may burn less or more efficiently in the given engine and increase or decrease fuel mileage. It happens in a car. Add ethanol to gasoline and your fuel economy goes down. Add other hydrocarbons, like anti-knocking agents, and your efficiency goes up.

Nobody even bats an eye during this discussion, instead, they get a no-shit look on their face, or better yet, say it. When I turn the conversation to the human body, all of a sudden it becomes unbelievable. What? Different ratios of fat, protein and carbs can cause different amounts of energy to be wasted in the body? That’s bullshit…a calorie is a calorie.

Sorry big-box trainers and the equivalent ilk: the body obeys the 2nd law of thermodynamics as it does the 1st and therefore varies in efficiency based on activity, hormonal status and—by far the most important factor—the type of fuel we provide. That’s why Atwater, the father of the 4-4-9 calorie values for carbs, protein, and fat, respectively, distinguished between physical fuel values and physiological fuel values16. The first, physical fuel values, is the amount of energy you can get out of food by burning it with oxygen, literally. You throw food in a fancy oven, incinerate then record the total amount of heat released—this is the physical fuel value.

The physiological value is the amount of energy the organism can derive from the fuel, which can be lower or higher. Fat, for example, depending on if the body is in a growth stage can get over 11 calories per gram out of fat17-21. That’s significantly more than the 9 listed on candy bar wrappers. This is a consistent result of measurement. Clearly, even a calorie of fat is not a calorie of fat. If you understand chemistry or statistical mechanics, nothing should seem odd about this. The body may burn fat using one set of enzymes over another—like the difference between aerobic (burning in the presence of oxygen) and anaerobic (burning in the absence of oxygen)—or may upregulate the production of fat burning enzymes to make the whole process more efficient. These two require different enzymes and other molecules. Different or accelerated avenues of metabolization can produce different amounts of energy.

The physical and physiological fuel values don’t match up for protein either. It takes energy to process the food we eat, energy that’s wasted as heat known as the thermic effect of feeding (TEF). When you eat a meal, you warm up. It’s that simple. There’s an extensive amount of research on the subject: about 2% of the ingested calories of fat, 7% of carbs and 30% of protein is wasted as heat whenever you eat22.

Let’s stop for a second. This is well established fact. There’s no disagreement in the scientific community, amongst pop-diet writers, not even among medical professionals. Knowing this, you can calculate the difference in physiological fuel values between two identical diets. If you took a diet that is 60% carbohydrates, swapped it around so that a much larger percentage of the calories came from protein, you could create two different 2000 calorie diets, one that’s high-carb providing 1850 physiological calories (considering all the heat lost) and one that’s low-carb providing about 1700 physiological calories (even more heat loss). By shuffling things around, we cut 150 usable calories per day while still putting 2000 calories into our mouths.

I’m going to say what is hopefully obvious at this point: being inefficient is good if you love food. If you can make your body inefficient, you can eat more and actually lose weight. My different dieting strategies—Carb Nite® and Carb Back-Loading™—both depend on manipulating TEF and other factors to make the body as inefficient as possible at the right times. Take Carb Nite for example: the diet is refined to the point that each time you consume carbs during the specified window of time, your body almost literally cannot store the carbs as fat, and works so hard trying to process them that it releases a ton of heat, you start sweating and the vascularity on your forearms doubles as a satellite map of the Amazon delta. All of these effects depend on enzyme activity and hormone levels, all of which can be manipulated by the food we eat.

A calorie is not a calorie: end of story. The whole argument is essentially one of laziness and ignorance. Our latest dietary iconoclasts accept one set of facts, but refuse to accept another set of facts (yes, it’s a fact that you can make your body more or less efficient, that a calorie is not a calorie, so to speak). A calorie is not a calorie is a direct consequence of the accepted facts. Maybe we’re not taught to think logically anymore, to understand cause-and-effect because truthfully, the conclusion that a calorie is not a calorie could be reached by any four-year-old who’s learned to play connect-the-dots.

1.     Feinman RD, Fine EJ. Nonequilibrium thermodynamics and energy efficiency in weight loss diets. Theor Biol Med Model. 2007 Jul 30;4:27. Review.

2.     Feinman RD, Fine EJ. Thermodynamics and metabolic advantage of weight loss diets. Metab Syndr Relat Disord. 2003 Sep;1(3):209-19.

3.     Fine EJ, Feinman RD. Thermodynamics of weight loss diets. Nutr Metab (Lond). 2004 Dec 8;1(1):15.

4.     Feinman RD, Fine EJ. Whatever happened to the second law of thermodynamics? Am J Clin Nutr. 2004 Nov;80(5):1445-6; author reply 1446.

5.     Rabast U, Kasper H, Schonborn J. Comparative studies in obese subjects fed carbohydrate-restricted and high carbohydrate 1,000-calorie formula diets. Nutr Metab 1978, 22:269-77.

6.     Rabast U, Hahn A, Reiners C, Ehl M. Thyroid hormone changes in obese subjects during fasting and a very-low-calorie diet. Int J Obes 1981, 5:305-11.

7.     Golay A, Eigenheer C, Morel Y, Kujawski P, Lehmann T, de Tonnac N. Weight-loss with low or high carbohydrate diet? Int J Obes Relat Metab Disord 1996, 20:1067-72.

8.     Golay A, Allaz AF, Morel Y, de Tonnac N, Tankova S, Reaven G. Similar weight loss with low- or high-carbohydrate diets. Am J Clin Nutr 1996, 63:174-8.

9.     Layman DK, Boileau RA, Erickson DJ, Painter JE, Shiue H, Sather C, Christou DD. A reduced ratio of dietary carbohydrate to protein improves body composition and blood lipid profiles during weight loss in adult women. J Nutr 2003, 133:411-7.

10.  Lean ME, Han TS, Prvan T, Richmond PR, Avenell A. Weight loss with high and low carbohydrate 1200 kcal diets in free living women. Eur J Clin Nutr 1997, 51:243-8.

11.  Baba NH, Sawaya S, Torbay N, Habbal Z, Azar S, Hashim SA. High protein vs high carbohydrate hypoenergetic diet for the treatment of obese hyperinsulinemic subjects. Int J Obes Relat Metab Disord 1999, 23:1202-6.

12.  Young CM, Scanlan SS, Im HS, Lutwak L. Effect of body composition and other parameters in obese young men of carbohydrate level of reduction diet. Am J Clin Nutr 1971, 24:290-6.

13.  Greene P, Willett W, Devecis J, Skaf A. Pilot 12-Week Feeding Weight-Loss Comparison: Low-Fat vs Low-Carbohydrate (Ketogenic) Diets. Obesity Research 2003, 11:A23.

14.  Riggs AJ, White BD, Gropper SS. Changes in energy expenditure associated with ingestion of high protein, high fat versus high protein, low fat meals among underweight, normal weight, and overweight females. Nutr J. 2007 Nov 12;6:40.

15.  Reinus JF, Heymsfield SB, Wiskind R, Casper K, Galambos JT.  Ethanol: relative fuel value and metabolic effects in vivo.  Metabolism. 1989 Feb;38(2):125-35.

16.  Atwater WO, Woods CD.  The availability and fuel values of food materials.  In Connecticut (Storrs) Agricultural Experiment Station 12th Annual Report (Storrs, CT).  1900; 73-123.

17.  Carew LB Jr, Hill FW.  Effect of corn oil on metabolic efficiency of energy utilization by chicks.  J Nutr. 1964 Aug;83:293-9.

18.  Carew LB Jr, Hopkins DT, Nesheim MC.  Influence of amount and type of fat on metabolic efficiency of energy utilization by the chick.  J Nutr. 1964 Aug;83:300-6.

19.  Donato K, Hegsted DM.  Efficiency of utilization of various sources of energy for growth.  Proc Natl Acad Sci U S A. 1985 Aug;82(15):4866-70.

20.  Donato KA.  Efficiency and utilization of various energy sources for growth.  Am J Clin Nutr. 1987 Jan;45(1 Suppl):164-7.

21.  Pi-Sunyer FX. Metabolic efficiency of macronutrient utilization in humans. Crit Rev Food Sci Nutr. 1993;33(4-5):359-61. Review.

22.  Jequier E. Pathways to obesity. Int J Obes Relat Metab Disord 2002, 26 Suppl 2:S12-7. Review.

Loading Comments... Loading Comments...