Wilbur Olin Atwater was an American chemist known for his studies of human nutrition

Human nutrition

Human nutrition is the provision to humans to obtain the materials necessary to support life. In general, humans can survive for two to eight weeks without food, depending on stored body fat and muscle mass. Survival without water is usually limited to three or four days...

 and metabolism

Metabolism

Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

.

Atwater grew up in the New England area. He opted not to fight in the American Civil War

American Civil War

The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 and instead to pursue an undergraduate degree at Wesleyan University

Wesleyan University

Wesleyan University is a private liberal arts college founded in 1831 and located in Middletown, Connecticut. According to the Carnegie Foundation for the Advancement of Teaching, Wesleyan is the only Baccalaureate College in the nation that emphasizes undergraduate instruction in the arts and...

 in Connecticut

Connecticut

Connecticut is a state in the New England region of the northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, and the state of New York to the west and the south .Connecticut is named for the Connecticut River, the major U.S. river that approximately...

. In 1868, Atwater's interest in civil engineering

Civil engineering

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like roads, bridges, canals, dams, and buildings...

 and agricultural chemistry

Agricultural chemistry

Agricultural chemistry is the study of both chemistry and biochemistry which are important in agricultural production, the processing of raw products into foods and beverages, and in environmental monitoring and remediation...

 led him to enroll in Yale University

Yale University

Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

's Sheffield Scientific School

Sheffield Scientific School

Sheffield Scientific School was founded in 1847 as a school of Yale College in New Haven, Connecticut for instruction in science and engineering. Originally named the Yale Scientific School, it was renamed in 1861 in honor of Joseph E. Sheffield, the railroad executive. The school was...

, where he analyzed agricultural fertilizers for specific mineral content. Atwater received his doctorate

Doctorate

A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...

 in 1869 in agricultural chemistry, his thesis being entitled "The Proximate Composition of Several Types of American Maize." Afterwards, he spent two years in Leipzig

Leipzig

Leipzig Leipzig has always been a trade city, situated during the time of the Holy Roman Empire at the intersection of the Via Regia and Via Imperii, two important trade routes. At one time, Leipzig was one of the major European centres of learning and culture in fields such as music and publishing...

 and Berlin

Berlin

Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, where he visited agricultural experiment stations. Atwater also spent time traveling throughout Scotland

Scotland

Scotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...

, Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

, and Naples

Naples

Naples is a city in Southern Italy, situated on the country's west coast by the Gulf of Naples. Lying between two notable volcanic regions, Mount Vesuvius and the Phlegraean Fields, it is the capital of the region of Campania and of the province of Naples...

, where he reported his findings in local newspapers distributed where he lived back in the United States. Atwater later returned to the United States to teach at East Tennessee University and later Wesleyan as its first Professor of Chemistry.

His granddaughter Catherine Merriam Atwater

Catherine Galbraith

Catherine "Kitty" Galbraith , née Catherine Merriam Atwater, was an American author who was the wife of economist and author John Kenneth Galbraith, and the mother of four sons: diplomat and political analyst, Peter W. Galbraith, economist James K. Galbraith, attorney J...

 married economist John Kenneth Galbraith

John Kenneth Galbraith

John Kenneth "Ken" Galbraith , OC was a Canadian-American economist. He was a Keynesian and an institutionalist, a leading proponent of 20th-century American liberalism...

.

Scientific advancement

Atwater is best known for his studies of human nutrition. He invented and utilized the respiration calorimeter, with the help of fellow Wesleyan scientists Edward Bennett Rosa

Edward Bennett Rosa

Edward Bennett Rosa was an American physicist, specialising in measurement science....

 and Francis Gano Benedict

Francis Gano Benedict

Francis Gano Benedict was an American nutritionist who developed a calorimeter and a spirometer used to determine oxygen consumption and measure metabolic rate....

, to measure precisely the energy provided by food and created a system to measure that energy in units, known as food calories as developed in the Atwater system

Atwater system

The Atwater system or derivatives of this system are used for the calculation of the available energy of foods. The system was developed largely from the experimental studies of Atwater and his colleagues in the later part of the 19th century and the early years of the 20th at Wesleyan University...

. "Maintained in the basement of Judd Hall [at Wesleyan], the 4- by 8-foot chamber housed a machine that measured human oxygen intake and carbon dioxide output."

With annual costs exceeding ten thousand dollars, the respiration calorimeter was considered a dream project for the nineteenth century. Atwater began the first of about 500 experiments in 1896. He studied respiration and metabolism in animals and in humans. The calorimeter aided studies in food analysis, dietary evolution, work energy consumption, and digestible foods. It measured the human metabolism balance by analyzing the heat

Heat

In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...

 produced and metabolic rate by a person performing certain physical activities. With this machine, the dynamics of metabolism could be quantified and the balance between food intake and energy output could be measured. Atwater applied the first law of thermodynamics

First law of thermodynamics

The first law of thermodynamics is an expression of the principle of conservation of work.The law states that energy can be transformed, i.e. changed from one form to another, but cannot be created nor destroyed...

 to his research: Energy can be transformed (i.e., changed from one form to another), but energy can neither be created nor destroyed. Before Atwater's development of the respiration calorimeter, many experiments on calorie intake and expenditure had been conducted on animals. During this period, there was a widely held belief that the first law of thermodynamics applied to animals but did not apply to humans because they were unique. Atwater demonstrated that whatever amount of consumed energy humans can not use is left over and stored in the body. His findings thus established that the First Law applied to humans as well as animals. Atwater's research and conclusions in this regard changed both how people thought about science and about humans.

The results from Atwater’s calorimetry study influenced many areas of American life. Most importantly, the calorimeter was a great influence to the growing awareness of the food calorie as a unit of measure both in terms of consumption and metabolism. Atwater reported on the weight of the calorie as a means to measure the efficiency of a diet. He stated that different types of food produced different amounts of energy. He stressed the importance of an inexpensive and efficient diet that included more proteins, beans, and vegetables in place of carbohydrates. Atwater also studied the effect of alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 on the body. His findings showed that humans generated heat from alcohol just as humans generated heat from a carbohydrate. At a time when the Scientific Temperance Federation

Scientific Temperance Federation

The Scientific Temperance Federation was founded in 1906 upon the death of Mary Hunt, head of the Women’s Christian Temperance Union’s Department of Scientific Temperance Instruction.Mrs...

 and the Woman's Christian Temperance Union

Woman's Christian Temperance Union

The Woman's Christian Temperance Union was the first mass organization among women devoted to social reform with a program that "linked the religious and the secular through concerted and far-reaching reform strategies based on applied Christianity." Originally organized on December 23, 1873, in...

 doubted the nutritional value of alcohol, Atwater proved that alcohol could be oxidized in the body and used to some extent as fuel for the human motor. Information gained from Atwater’s experiments was used by the liquor trade in the promotion of alcohol. "[Atwater] was very prominent in the temperance movement, and every year he would lecture the students about temperance and tried to promote [abstention from alcohol]," ... "Being a good scientist, he reported the data and was very upset that alcohol companies used his research" to advertise their products.

Continuation of study

After completing his study, Atwater concluded that Americans consumed too much fat

Fat

Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...

 and sweets

SweetS

was a Japanese idol group. Put together through auditions, the group debuted in 2003 on the avex trax label. Although the group met minor success, they disbanded after three years with the release of a final single in June 2006....

 and did not exercise enough. His collaborator and successor at Wesleyan, Francis Benedict (1870–1957), continued down Atwater’s path using the respiration calorimeter to further measure metabolism and other bodily processes. Benedict studied the varying metabolism rates of infants born in two hospitals in Massachusetts, athletes, students, vegetarians, Mayans living in the Yucatán, and normal adults. He even developed a calorimeter large enough to hold twelve girl scouts for an extended period of time. His biggest improvement was the invention of portable field respiration calorimeters. In 1919, Francis Benedict published a metabolic standards report with extensive tables based on age, sex, height, and weight.

External links

• Wilbur Atwater at Find-A-Grave