A back view of Atwater’s respiration calorimeter. Image courtesy Wesleyan University Library, Special Collections & Archives.
The Hollywood 18-Day Diet, for example, restricted dieters to a spartan ration of citrus fruits, melba toast, vegetables, and hard-boiled eggs, amounting to 585 calories per day. Calorie counting reinforced dieting practices already under way and encouraged new dieters by legitimating its promise with science.
If Atwater introduced the calorie to American nutrition science, Lulu Hunt Peters was the self-proclaimed “popularizer” of calories. A physician of the Progressive era—then an unusual profession for a woman—Peters earned a medical degree from the University of California in 1909. Her personal struggles with weight and her own relative success with counting calories informed her conviction that managing calorie consumption was the answer to weight control. By her own account Peters weighed 220 pounds at her heaviest, then lost 70 pounds through calorie restriction. Still, Peters never achieved a certifiably slender frame, such as those seen on gossamer contemporaries like the French fashion designer Coco Chanel and the infamous Duchess of Windsor (the erstwhile American divorcée, Wallis Simpson). In middle age Peters had the appearance of a perennial, intermittently frustrated dieter. But as would be expected of the doyenne of calorie counting, Peters was unmistakably fashionable. She adorned herself in conspicuous jewelry and furs. Her eyebrows were severely plucked, and her thin, pursed lips enhanced with bold lipstick. Her dark hair was bobbed and ornamented with low-hanging headbands. Everything about Peters’s physical presentation conveyed a sense of exacting obeisance to the dictates of flapper fashion. In this sense she was just like her acolytes—image-conscious and desperate to be thin.
From 1918 until her death Peters promoted calorie counting for weight loss through her syndicated column and diet guides. Like Atwater, Peters was both an adept and indefatigable advocate for herself and the calorie as a precise, infallible measurement of food. But while Atwater proposed counting calories to achieve physiological efficiency and equilibrium, Peters did so primarily as a tool to manipulate one’s weight for aesthetic ends. In promoting calorie counting as a way of life, she projected an assertive, didactic voice. She lectured in Diet and Health (the book for which she is remembered), “You should know and also use the word calorie as frequently, or more frequently, than you use the words foot, yard, quart, gallon, and so forth, as measures of length and liquids. Hereafter you are going to eat calories of food. Instead of saying one slice of bread, or a piece of pie, you will say 100 calories of bread, 350 calories of pie.”
In insisting that dieters reimagine food as calories, Peters encouraged what amounted to a mathematization of dieting. Her mantra was that if dieters learned how many calories they would need to consume in order to lose weight and how many calories were contained in the foods they ate, they would be equipped to melt off the pounds. According to the diet guru, the average person should consume 15 to 20 calories per pound of body weight daily in order to maintain weight. Dieters were to subtract that total by 500 to 1000 calories a day, depending on how rapidly they hoped to lose weight. Given the tallying involved in this regimen, it was no wonder that Peters reserved pages in her diet guide for users to log their calorie counts.
Diet and Health sold like calorie-laden hotcakes. Frequently cited as America’s first best-selling diet book, the book sold 2 million copies—800,000 in hardcover—and was in continuous publication from 1918 to 1939. In 1922 alone the 105-page book went through 9 printings and topped the New York Tribune’s list of best-selling nonfiction books. By 1930, the year Peters died, the word calorie seemed to roll off people’s tongues, and even some schoolchildren were fluent in calorie counting. In 1927 one home economist observed that “in this country the calorie is a familiar word in the vocabulary of practically every adult, and anyone who doubts the possibility of popularizing it should observe a group of ten-year-old children counting their calories.”
As her book sales indicated, Peters had a substantial fan base. Her program of calorie counting made dieting seem more scientific and failure-proof. To be able to quantify and manipulate food intake accordingly gave dieters a newfound feeling of control over the size and shape of their bodies. Calorie counting, moreover, was a social pastime of sorts that women shared with their friends.