September 22: The Man Who Proved We Are What We Eat


Wilbur Olin Atwater (USDA MAL Special Collections)

Wilbur Olin Atwater, who died today in 1907, was a nineteenth-century pioneer in nutrition science who talked about food and metabolism 150 years ago in a way that would seem totally at home on the pages of a health magazine or nutrition brochure today. The son of a New York minister and librarian, Atwater attended Wesleyan University and graduate school at Yale, where he got his PhD in 1869 for a thesis studying the chemical makeup of corn in dizzying detail.

Though lacking an epicurean interest in food, Atwater wanted to know everything about it on the tiniest scale: he wanted to know if humans really are what we eat, and how we might change our bodies or energy levels based on what we put into our mouths.

Unknown. circa 1907. “Subject on bicycle ergometer.” Special Collections, USDA National Agricultural Library.

After receiving his doctorate, Atwater further developed his toolkit, working in agriculture, physiology and chemistry to pick apart the nutritive values of various fertilizers and foods ranging  from fish to beans. Curious about how growth and the consumption of food might affect energy in the human body, Atwater studied metabolism in Germany. Noticing that European researchers used a model that leaned on the use of experimental agricultural stations, he became eager to set up a similar sort of practical farm lab in the United States. On his return to the states, Atwater implemented an experimental farm facility at Wesleyan for research purposes, the first of its kind in America.

Unknown. circa 1907. “Calorimeter subject washing clothes, Washington D.C..” Special Collections, USDA National Agricultural Library.

This facility, and the addition of government funding, meant that Atwater and his colleagues could dig into nutrition research. Their reports included information that would be very familiar to the modern fitness enthusiast:  about food’s macronutrients and energy value, about how bodies turn food into fuel, and how changes in exercise or diet could help both athletes’ performance and everyday health. The passage of the federal Hatch Act in 1887 meant that land-grant colleges could access money for agricultural stations, and Atwater was named director of Connecticut’s second station at the Storrs Agricultural College (now UConn).

Wilbur Olin Atwater’s other major contribution to nutrition science was the development of a calorimeter for measuring actual energy use in the human body. The machine worked, at its most basic, by measuring the heat a person produced after eating certain foods and going through physical activity. It could not have been terribly comfortable – it was, basically, a box that measured 7 by 4 by 6 feet and acted as the world’s smallest studio apartment for the experiment subject – but it effectively measured calorie information and allowed Atwater and his teams to demonstrate that people burned food for fuel, and stored as fat what they couldn’t burn.

Atwater’s legacy continues today in both agricultural research and nutrition – the USDA food charts and nutrition guidance you may remember from your school days have their roots in the nutrition research he  conducted many years ago.

Unknown. 1910. “Subject emerging from large respiration calorimeter.” Special Collections, USDA National Agricultural Library.


Further Reading

Frank I Katch, “Wilbur Olin Atwater,” History Makers

Pau Martin, “Olympians Owe Gold Standard to a Nineteenth-Century Chemist,” Fox News

Wilbur Olin Atwater Papers” NAL Special Collections

Wilbur Olin Atwater & Francis Gano Benedict, Experiments on the Metabolism of Matter and Energy in the Human Body, 1898-1900.“ Internet Archive