Friends, Romans, countrymen, lend me your ears; I come to bury Caesar, not to praise him. The evil that men do lives after them; the good is oft interred with their bones; […]From Julius Caesar, spoken by Mark Anthony
I come to bury calories, not to praise them. We consumers need a better term if we are going to beat the obesity epidemic. For the consumer, the word “calorie” should be put in quotation marks. Our lack of understanding of calories and how they fit into our diet plan has led to a proliferation of unsound diets. Image by carolynabooth from Pixabay
Be still my beating heart!
Maybe the thought of abandoning the calorie concept sent a rush of adrenalin through your system because you remember how you lost 50 pounds by counting calories. Maybe you’re convinced I’ve lost it. Fear not. Much about the calorie concept still works for the consumer, but some things don’t.
The Calorie Concept has Historical Relevance for Dieters
The logic behind the calories in – calories out model which we all believe to be the be all end all of weight loss is being revised as we discover new facts about the way the body uses the foods we eat.
As you learn the principles behind the cherished calorie concept, remember that the pioneering scholars who developed the calorie concept lived in the 18th and 19th centuries, and these scientists had few measurement tools at their disposal. They inferred or guessed what was happening inside the body based upon what was put into the body and what the body released.
Honor the History of Calories
The history of the calorie can be told by remembering a series of lives. This is a fragmentary history. For a deeper understanding, see papers by several authors in the reference section.
If we ignore history or take it for granted, we would become orphans in time — castaways on a desert island called “the present” — with no idea of where we came from or where we are going.Rosenfeld, 2003
The Calorie: Defined
As a starting point, let’s agree upon definitions. The word calorie is a unit of energy, and it has two very different uses. If capitalized, the word refers to heat. If used in lower case, it refers to a food’s energy value. A Calorie is defined as the amount of heat which would raise the temperature of 1 kg of water by 1°C.
Calories In – Calories Out
The related concept we’ll be tracing through history is calories in – calories out. The model, derived from the first law of thermodynamics, describes the relationship between energy in the food eaten and the energy released or used. The model assumes that no energy is lost, and any energy not used by the body must be stored.
We calculate calories in by analyzing the energy content of the food we eat. This analysis is usually done with a calorimeter.
For our purposes, energy out is measured by an indirect calorimeter. we will divide calories used into three types — at rest, working or exercising, and energy used to fuel body processes. Note, other authors may break down energy out into different chunks. These differences are not important here.
- Energy expenditure at rest accounts for 70% of total energy expenditure.
- Energy expended when working or exercising accounts for 20% of total energy expenditure.
- Energy used by the body to fuel its processes accounts for 10% of total energy expenditure.
The history of the calories in – calories out concept begins with Antoine Lavoisier (1743-1794). He is one of the fathers of chemistry, and he is generally regarded as a scientific genius. Watch this YouTube video for a review of his vast scientific contributions.
The Caloric Theory of Heat
In the 18th century, scholars knew that the weight of the food we eat weighs more than the urine and feces we excrete. They thought this loss was due to perspiration. One writer jokingly noted, “Early researchers spent large amounts of their time studying human and animal waste products” (Stafford, 2010). Early scientists could only study waste products because they had no access to the internal workings of the body.
Lavoisier suggested that all objects contained different amounts of a heat producing caloric. If the invisible caloric energy flowed into an object, its temperature increased and vice versa.
Lavoisier’s Scientific Instruments
Lavoisier spent much of his fortune on research. Here are a few images of the instruments he designed. The top left device measures carbonic acid output. Lavoisier’s wife did the second etching of a distillation furnace. The apparatus in green is a combustion apparatus. The painting shows Lavoisier and his wife with a device of some sort on the table in front of him. Lavoisier’s best known instrument is the ice calorimeter, and this is shown in the next section. To read more about these instruments, follow this link. http://www.famousscientists.org/antoine-lavoisier/
Food as Fuel
Lavoisier wondered if the body behaved like the engines being developed at the time. Did the body burn food and expel carbon dioxide?
To answer this question, Lavoisier invented a simple ice calorimeter to measure calorics or heat.
Ice calorimeter used in 1782 to measure the heat required to melt ice.
How the Ice Calorimeter Works
The easiest way to understand the ice calorimeter is to study the cross-sectional view of the device. The object whose heat is to be measured is placed in the center chamber. The outer chamber is filled with ice. The chamber is sealed with a lid. The amount of energy or calorics in the object is determined by the amount of water/per unit time that is caught in the drip pan below.
Lavoisier’s Studies on Respiratory Gas
In one classic experiment, Lavoisier compared the heat produced by a living creature, the guinea pig with a lighted candle. Both caused the ice to melt. Lavoisier declared, “Respiratory gas exchange is a combustion like that of a candle burning” (Stafford, 2010).
Studying Calories Out
Lavoisier used the experimental setup below to study calories out via human respiratory gases. The subject is sitting at the end of the table and is breathing into a collection device.
A. Lavoisier working in his chemistry laboratory while his wife took notes.
Revolutionary Significance of Lavoisier’s Research
Lavoisier’s conclusions are commonplace today, but they were revolutionary in his time. Due to Lavoisier, we know that our bodies release energy and need energy to function. We also know that what goes on inside the body can be deduced from body byproducts such as expired air or waste products.
Science and Politics
Lavoisier is famous for another reason. His execution by guillotine during the French Revolution is often cited as an example of the dangers of mixing science and politics.
Lavoisier used his inheritance and his wife’s income to buy into the General Farm, the revenue collection arm of the French monarchy (taxes, tolls, and revenues). Later during the French Revolution, tax collectors became targets. The revolutionary government charged Lavoisier and 31 others with revenue fraud. They were tried in a farcical mass trial which lasted only a few hours. Lavoisier and the other revenue agents were guillotined and buried in a mass grave. For more, read https://io9.gizmodo.com/the-scientific-feud-that-ended-in-an-execution-6-6586522
Painting of Lavoisier’s execution by Jacques Louis David
Jean-Baptiste Boussingault Develops Concept of Balance Trials
Jean-Pierre Boussingault in a Napoleonic pose
In the 1830’s, the French chemist Jean Baptiste Boussingault (1801-1887) developed nutritional “balance trials”. Does what is put into the body match what the body puts out? Balance trials laid down the basis for the calories in – calories out concept.
Boussingault compared the amount of nitrogen, a constituent element of protein, in hay, oats, and potatoes fed to cows and horses with their excrement or milk. He wanted to know if plants contained sufficient nitrogen to meet the animals’ needs. At that time, scholars thought that animals obtained nitrogen from the air.
A Self-educated Man
Unlike many scientists of his day, Boussingault was poor and uneducated when he discovered his love of science. At age 12, this son of a retired soldier in Napoleon’s army got a job cleaning the laboratory of a respected chemist. When the chemist learned that the youth was conducting after hours experiments, he fired the boy.
Undeterred, Boussingault read chemistry books written by the very chemist who had fired him, and he attended free lectures. At age 16, he applied to a newly opened school of mines. Boussingault is best known for his work with iodine for the treatment of goiters.
James Joule — Beer Baron and Scholar
Lavoisier’s caloric theory held sway for nearly 100 years until several scientists independently proved that there was a better way to conceptualize the dynamics of heat. James Joule was one of these (1818-1889).
The gallery shows the Joule family brewery, a device to measure change of temperature of a fluid per input work, an electrical motor designed by Joule and presented to Kelvin. The photo is by Stephencdickson – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=67566447 The last image is a painting of Joule.
The Joule apparatus (center top) measures the change in temperature of a volume of fluid (heat) per input work (mechanical energy). The apparatus involves a thermometer, a chamber, a propeller submerged in the fluid, and a crank for the input work. When the crank is turned, the fluid is churned by the propeller, increasing the average kinetic energy of the particles. The device determines the relationship between mechanical energy and heat. The amount of energy required to raise 1 cc of water by 1 degree Celsius is a Joule.
James Joule Was a Driven Man
As history tells us, James Joule was picnicking near a waterfall in the Alps with his bride. Rather than attending to his new wife, James measured the temperature of the water at the top and the bottom of a nearby waterfall. Watch this delightful, fanciful depiction of the newlywed conversation.
Joule couldn’t replace the coal powered steam engines in the brewery, but he continued to experiment. In the mid 1800’s, he demonstrated that the same amount of work no matter however done always produced the same amount of energy. He determined that heat was a mechanical form of energy. Joule’s research led to the law of conservation of energy and the first law of thermodynamics.
First Law of Thermodynamics Doesn’t Hold for Food Processing
Since 1824, the notion that calories in must equal calories out has dominated nutrition. Another related idea is that a calorie is a calorie no matter the source. The model predicts that 100 calories from a piece of pie will produce the same energy in the human body as a piece of steak with the same number of calories. While this may be true for a machine, our bodies do not treat protein calories in the same way as those from carbohydrates or fats. We’ll talk more about that in part 2. I Come to Bury Calories -2
The Body as Machine
The calories in – calories out concept of how we metabolize food sees the body as a machine. The body is not a machine. Our bodies have no little men working in the brain, no pulleys moving our arms and legs, no bellows pumping air, and no furnace burning food.
An example of the mechanistic view of the human body is illustrated in the vintage drawing.
The mid-19th century physiological chemist, William Prout (1785-1850), was an exceptional man. His parents could not afford private schools, and his formal education ended when he was 13 years old. He continued to seek education and was eventually graduated from the University of Edinburgh Medical School.
Father of the Carbohydrate
Dr. Prout was a practicing physician, and he often forgot to charge his patients because he was eager to resume his experiments. Prout used his income to do experiments on a wide range of subjects.
Prout Identifies the Elements of Food
Prout earned the coveted Copley Prize in 1827 for his work, On the Ultimate Composition of Simple Elementary Substances, with Some Preliminary Remarks on the Analysis of Organized Bodies in General.
Prout was the first scientist to classify foods into what he called saccharinous (carbohydrates), albuminous (proteins), and oleaginous (fats) sustances. He developed expensive equipment of his own design to determine the exact composition of these major divisions of food and the changes that could be induced in them.
Justus von Liebig
Justus von Liebig (1803-1873), one of the founders of organic chemistry, was one of the greatest chemistry teachers of all time. His laboratory produced many famous chemists including von Voigt, von Pettenkaufer, and Atwater. Von Voit is considered the father of the fertilizer industry due to his interest in nitrogen and trace minerals.
von Liebig was interested in the elements of soil
He developed a manufacturing process for beef extract. His work was used to develop the first beef bouillon cube.
Vintage Oxo bullion cube container. The beef extract process was developed by von Leibig.
Overuse of the Land
In the mid-nineteenth century, large landowners rented small plots of land to tenant farmers. Many landowners were quick to adopt the new principles of agricultural science and chemistry, a practice called high farming. The wealthy landowners dominated agriculture sales.
Von Leibig, the First Ecologist?
Justus Von Leibig opposed the domination of land resources by a wealthy few, and he called their “high farming” an advanced robbery economy because it deprived small landowners of a share in agricultural profits. He was devoted to finding the cheapest and easiest ways to feed the poor.
No other human occupation opens so wide a field for the profitable and agreeable combination with cultivated thought, as agriculture.
Image of a campaign button for Lincoln’s presidential campaign from the Library of Congress
Abraham Lincoln, you scoff! What did he have to do with calorie counting?
With President Lincoln, we begin the history of nutrition in the United States. Lincoln worked to improve the science of agriculture. Among other acts, President Lincoln approved a bill which established the United States Department of Agriculture. The agency drew from the European scientific approach to farming. The new agency’s goals were to
Test by experiment the use of agricultural implements and the value of seeds, soils, manures and animals, undertake the chemical investigation of soils, grains, fruits, vegetables, and manures, and publishing the results.
Labs were established and scientists began studying the chemical components of food and the physiological processes of digestion by using calorimetry to break food down into calories, fats, proteins and carbohydrates.
Obesity and the Actuary
Trying to predict the future and control the risk to investors started in the marine shipping industry — what were the odds that a cargo would reach its destination? The principles of actuarial science were applied to other practical problems.
By the 17th century, John Graunt showed that there were predictable patterns of longevity and death in a group of people and that those patterns could be organized into life tables. Enter life insurance and the estimation of life expectancy or mortality. The figure shows the rapid growth in the insurance industry at the beginning of the twentieth century. For a history of actuarial science, see this post. http://Beginning and History of Actuarial Science | FUTURE-TRACK
The number of life insurance companies increased exponentially during the last decades of the 19th century.
Physicians began to consider actuarial data when advising their overweight patients to lose a few pounds. Early actuarial tables showed that being overweight shortened life expectancy.
Wilbur O. Atwater Established the First Scientific Network to Study Food in the U.S.
Dr. Atwater (1844-1907) was a chemist and an able politician. With the support of President Grover Cleveland, he obtained federal funding for experimental agricultural research stations.
Like other German researchers with whom he had studied in von Liebig’s laboratory, Atwater wanted to find better ways to get the most work out of the human machine by identifying the best fuels.
Measuring Energy In
Dr. Atwater drew upon the resources of the newly established experimental agriculture stations. Between 1844 and 1907, Atwater and E. Rosa compiled 5,000 analyses from the experimental stations to determine the calorie value of many foods. They created the first food tables and charts to include the energy values of moisture, protein, fat, total carbohydrate and ash in foods.
Atwater’s measurements were so precise that his energy equivalents for protein, fat and carbohydrate are still used today.
Atwater coined and defined the word, calorie. A calorie of food energy equals 1,000 calories of thermal energy.
Energy values of nutrients in the Atwater System
The Atwater system uses a single energy value for each of the main groups of macronutrients: protein, fat, and carbohydrate. In the Atwater system, these energy values are constant no matter which food is being considered. According to Atwater, the energy values of the macronutrients are the following:
- Proteins contain 4 calories of energy.
- Fats contain 9 calories of energy.
- Carbohydrates contain 4 calories of energy.
The Atwater System is still used.
The Bomb Calorimeter
Atwater designed a version of the bomb calorimeter to calculate the energy values of foods in the Atwater System.
The bomb calorimeter, so-named because its chambers resembled those of bombs of the day, burns a food sample completely. The heat resulting from the burn is transferred to water in the surrounding combustion chamber. The increase of the water’s temperature is used to calculate the calorie value of the food sample. This value is the gross energy value of the food. Bomb calorimetry gave us the phrase, “burn calories”.
This video shows how a modern calorimeter is used to determine calories.
Burning Calories Is a Misnomer When Applied to Food
Stop thinking or saying you’ve burned so many calories when you exercise or work. Measuring food energy in a calorimeter differs from the way in which the body uses a food. Don’t think that you can eat a piece of chocolate cake and then walk it off. Not only is this inaccurate, but it’s the first step toward an eating disorder. We’ll talk more about this in part 2.
Measuring Energy Out
Atwater used Indirect Calorimetry to study how much energy was used by the body.
Indirect calorimetry is the measurement of heat produced by an animal through the determination of the oxygen consumed and the carbon dioxide eliminated. Through indirect calorimetry, substrate or food utilization can be estimated using the respiratory exchange ratio calculated by dividing carbon dioxide produced (VCO2) by oxygen consumed (VO2). The nutritional respiratory exchange rate (RER) range is 0.7 to 1.0, with 0.7 corresponding to predominantly fat utilization and 1.0 to predominantly carbohydrate utilization.
Atwater’s Respiratory Chamber
Atwater and colleagues redesigned the indirect respiratory calorimeter used in von Leibig’s laboratory. Their calorimeter was a 4 x 8-foot chamber which was large enough for human subjects. Inside the chamber, a machine measured oxygen intake and carbon dioxide output. Thus, the apparatus could measure the metabolic balance of a person performing a physical activity or at rest.
Atwater applied the first law of thermodynamics, energy in = energy out, and he was the first to suggest that the energy difference between the amount of food that went in and the amount used must be stored in the body. It was assumed that the excess energy went into fat stores.
The image below shows the sealed Atwater-Benedict Chamber used to study energy output.
Man Is an Animal
Prior to Atwater, the law of thermodynamics was applied to animals but not to man. Scientists believed that the first law of thermodynamics didn’t apply to man. Atwater’s work helped to change the view that man is unique in the animal kingdom.
Atwater’s Research Taught Us
- Different foods produce different amounts of energy.
- The energy value of foods can be reliably measured.
- The consumer can design a diet which meets their goals for weight loss or weight gain.
- The consumer can choose foods which maximize health.
- Being overweight was caused by eating too much of the wrong foods.
Atwater Was Concerned About the Diet in the U.S.
Atwater’s last major publication was the Farmers Bulletin #142 (1904). Atwater worried that people in the United States were eating too much fat and sweets and did not exercise enough. Sound familar?
It is a fair question whether the results of these things have induced among us in a large class of well-to-do people, with little muscular activity, a habit of excessive eating (particularly of fats and sweets) and may be responsible for great damage to the health, to say nothing of the purse.
Food and Fashion
In the 19th century, the scientists’ main goal was to find inexpensive ways to supply enough food energy to feed a starving population. Americans and most Europeans associated plumpness with beauty and wealth. Being thin implied illness or poverty. Thus, the hour glass figure with its slim waist, full bust, and wide hips was the standard for feminine beauty.
During the 18th century, food became more plentiful, and people in the U.S. were growing taller and heavier. The Victorian vision of beauty was shifting along with the place and rights of women in society. Women wanted to throw away their corsets, show more skin, and bob their hair. More than anything, they wanted to lose weight.
Thin is in!
1920 Vogue magazine fashion photo, Library of Congress
Weight Loss Products Flooded the American Markets
Women (and perhaps a few men) bought sanitized tapeworms in capsule form. The tapeworms would eat the excess calories, and the woman would lose weight
Then as now, an incredible number of weight loss products hit the market. Some of these were
- Rolling pins to roll off the extra pounds
- Therapeutic baths
- Diets including specific nutrients. See theories of Graham about exercise and diet. Food Rituals, Addiction & S’mores
- Exercise and exercise machines of all types
- Thyroid extract
The Queen of Calorie Counting
Lulu Hunt Peters (1863-1930) represented the changing lives of women in the U.S. She graduated from medical school in 1909, a time when few women were enrolled in medical schools. She was the best known woman physician in the U.S. in the 1920’s.
Dr. Peters Started the Science of Weight Loss
Dr. Peters introduced Atwater’s concepts to the public and taught her readers that some weight loss methods were unscientific and dangerous. In her syndicated column, Diet and Health, she described her own weight loss. She lost 70 pounds on a diet she designed based upon the Atwater factors. She told women that they should count their calories if they wanted to be thin and in.
You haven’t eaten a piece of pie, you’ve eaten 350 calories.
Self-esteem and Well-Being Are Linked to Weight
I’m not sure if I want to congratulate Dr. Peters for this contribution to our collective thought. To Dr. Peters, dieting and being thin meant both being beautiful and being in total control of one’s self. She introduced the notion that thinness was an issue of self-esteem as well as physical health. This linkage between weight and self-worth continues to plague us today.
Lulu Hunt Peters, M.D. was the epitome of fashion in the early 20th century with dark lipstick, bobbed hair, the latest fashions, and a continuous struggle to be thin.
First Diet Book
Drawing from her columns, Dr. Peters published the first edition of Diet and Health with a Key to the Calories in 1918. Below is the sample menu from Dr. Peter’s book. It is presented without changes. Note that this menu fits in most modern diet books. (C = calories)
|One slice very dry coarse bread toast ¼ inch thick||50 C.|
|Butter, one quarter cubic inch||25|
|Hot water flavored with coffee||0|
|One corn muffin — I am patriotic||125 C.|
|One pat butter||100|
|1 cup coffee with one tablespoon cream||50|
|Vegetable soup or bullion, no fat||25 C.|
|Lean meat or lobster or fish, five or 6 ounces||300|
|Large serving of uncooked lettuce or cabbage||Zero|
|Mayonnaise or oil, ½ teaspoon||50|
|One large dish tomatoes, or vegetable||25|
|One medium slice bread, or one medium potato||100|
|1 cup cereal coffee, clear||0|
Dr. Peters Goes to Bosnia
Lulu Hunt Peters, M.D. physician in American Women’s Hospitals
In 1921, Dr. Peters added a chapter to her book. She had spent 2 years with the American Red Cross in Albania. She lived in rough conditions, and she described her experience in her revised manuscript.
We had to work hard and expend a great deal of nervous energy. Medical calls on foot in the scorching sun over unkind cobblestones, long distance calls on unkinder mules, long hours in nerve-wracking clinics, ferocious man-eating mosquitos, scorpions, centipedes, sandflies, fleas, and other unspeakable animals kept us hopping and slapping and scratching.
Suddenly a Best-Selling Author
When Dr. Peters returned home, her book was a best seller and in its fifth edition. At the request of her publishers, she added a chapter with more recipes.
Dr. Peters First Diet Book Lived After Her
Dr. Peters died in 1930, but her book lived after her. The book was in its 55th printing in 1939. Although most diet books lack Dr. Peters light, personal, and humorous touch, all contemporary diet books draw from her work.
Copies of the book may be purchased from a number of retail outlets; however, you can download her book at no charge from the Gutenberg Project http://www.guttenbergproject.com. Why pay retail?
Burying the Calorie
This brief history presents some of the key milestones in our thinking about the energy in foods and how it is used. This history proves that the calorie in – calorie out concept is dated. Yet most of us continue to believe in it and many authors continue to teach it.
We’re Stuck in the Nineteenth Century
When it comes to our concept of calories and weight loss, we’re lost in a time warp. We’re living the ideas of the 19th and early 20th centuries. We continue to apply mechanical concepts to food and nutrition. We continue to follow dietary advice that is so dated that it creaks.
This might be amusing were it not for the fact that these dated ideas keep us both ignorant and fat. Throw away your calorie counters and your calorie reference books. You can count calories until you’re green, but you won’t necessarily lose weight. If you are counting calories and losing weight, the real reason you’re losing weight is you’re eating a smaller amount of better quality food.
Calorie Counting Is the Model-T of Dieting
Think of calorie counting and the calories in – calories out model as an outdated car. The Model B Ford was the car to drive in 1904, the year Atwater’s calorie tables were released. The Model B was a fine car, but I wouldn’t want to drive one on today’s freeways.
Ford Model B was Ford’s first car to use a front-engine layout, and it featured a 24- hp-4-cylinder engine positioned at the front. A stripped down version set a speed record of 91 mph!
Issues with the Calorie Concept
The calorie concept as thought of by most of us is flawed in the following ways:
- There is much more to food than protein, fat, and carbohydrates as assumed by the calories in – calories out model. Micronutrients are essential to food metabolism and our body weight.
- All food calories are not equal from the body’s perspective. The body does different things with a protein as opposed to a fat.
- New calorie studies don’t precisely match Atwater’s findings.
- Fat is much more than a storage bin for excess energy.
- All bodies are not equal. The body is not a machine, and individuals metabolize foods differently.
- External conditions affect the way the body processes calories. Calorie reduction, for example, changes the way the body processes food.
- Increasing exercise is not an antidote for overeating.
Maybe I’ve torn up your little conceptual calorie counting world. I particularly apologize to Weight Watchers devotees. Don’t stop what you’re doing, but you can improve what you’re doing.
In part 2 of “I’ve Come to Bury Calories,” I’ll get you up to speed to what researchers are learning about the calories in – calories out model and how food is processed by our bodies. I Come to Bury Calories -2
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