The understanding that women are more likely to be fat than men and need fewer calories is common sense and counts as a truism in today’s nutritional discourse. Yet it has a relatively young history, one that shows how nutritional science contributes to shaping gender difference and ultimately putting women in their place. In the late 19^th and early 20^th century, nutritional research legitimized an unequal access to food for men and women and created fatness as a problem of passive women unable to keep up with modern times.

 

Dietary Studies and Women’s Food Needs

In the late 19^th century US, nutritional science emerged in a society shaped by the belief that scientific expertise—especially on bodies—was key to individual improvement and social progress at large. Scientists of different disciplines created knowledge about the inner workings of human bodies in order to understand and improve them. An understanding of how bodies were working, what they needed to labor and thrive, was deemed essential in the “race for life,” in fending off bodily decay caused by “over-civilization,” and in improving individual and collective health and fitness. Not surprisingly, food became an important field of study, and chemists, physiologists and home economists dedicated their research to the classification of nutrients, the workings of metabolism, and the dietary needs of bodies doing different kinds of physical work. In the US and Europe, the promises of food research as pathway to social progress fueled extensive laboratory research as well as hundreds of dietary studies that time and again revolved around the question of the food needs of male and female bodies. For these dietary studies, nutritionists or home economists—oftentimes women—visited homes all over the US, documented the food that was eaten and analyzed its content of nutrients and energy.

In order to compare the data of different families and studies, the surveyors aimed at calculating the amount of nutrients and energy “per man per day.” For this purpose, they counted all the foods a family had eaten and divided them by the—theoretically calculated—number of male adults. While women and children were included in this calculation, they counted as only 80 per cent and less of male adults, regardless of the kind of work they did and how big or heavy they were. This figure was set rather randomly, partly based on “arbitrary assumptions,” as one report on these studies declared (p. 6).

This account of women needing only 80 per cent of the men’s food rations had high symbolic power. It seized an everyday understanding of women’s food needs and turned it into a matter of fact, normalizing gender difference and an unequal access to food. The reports refer to wives, laboring or not, who were making sure that their husbands and other male family members had enough to eat before they dispensed the leftovers—if there was some left—to their children and themselves. The studies set the benchmarks for later dietary studies and even had an impact on global dietary surveys conceptualized by the League of Nations Health Organization in the 1930s. Moreover, their account of women’s lower caloric needs influenced research on the basal metabolism of bodies.

In the early 20^th century, nutritional scientists revisited the question of male and female dietary needs and found those “arbitrary assumptions” confirmed. Women needed fewer calories than men, they claimed, because their bodies were producing less heat than men’s. The experiments authorized the scientists’ expectations: Men and women differed not only in their external muscular labor but also in the basic energy needs of their bodies. Even when comparing men and women of the same height and weight, men needed about five to six per cent more calories than women, the experiments suggested. They thereby provided a scientifically authorized explanation for assigning women less to eat.

 

Making Fat a Female Challenge

That women needed fewer calories was not considered a more efficient way to metabolize food—as a turn-of-the-century efficiency enthusiast could have understood it. Rather, it seemed to evidence that women had slower—and cooler—bodies. Men’s “body fires are burning faster,” a newspaper article on the experiments summarized their results in 1931, thereby explaining “Why Women Keep Cooler Than Men.” While the article, published in July, aimed at informing their readers why women suffered less from hot weather, the notion that men burned their food faster and were thus producing more heat had other repercussions for understanding female bodies. It contributed to making fat into a problem of women and rendered them unable to keep up with the modern pace.

The nutritional scientists explained the difference between male and female caloric requirements by referring to variations in their internal activity: Men had a larger “proportion of active protoplasmic tissue” while female bodies “had a much larger proportion of subcutaneous fat.” This distinction between manly active tissue and passive female fat stabilized a link between body fat, inertness, and femininity.

In the decades after 1900, the association of body fat and fat bodies with immobility and passivity seemed not as self-evident as today, but was increasingly dominant. In a society where many people were afraid of becoming too “soft” to face the challenges of modernity, fat became suspicious. It served as an antithesis to the mobility and efficiency required of modern bodies and selves. In this regard, dieting emerged as a practice of the middle class, demonstrating the ability of voluntary sacrifice and self-control in the face of abundance. Dietary advice books like the successful “Diet and Health with Key to the Calories” (1918) fueled this shift, calling fat people “fireless cookers” (p. 14) who moved less and could not burn their food properly, thus depositing it as fat. For the author of the book, physician Lulu Hunt Peters, fat was “virtually dead tissue.”

Peters’ book was also among the first books of fat-loss advice directed mainly to women. Earlier diets were rather a manly domain since only they were considered to possess the self-control required for successful dieting. When Peters challenged her fellow females to fight their “flabby” bodies and minds, she invoked these older constructions of femininity as passive and lacking of self-discipline. Early 20^th century metabolism research and advice contributed to feminizing fat—and fattening femininity—by rendering both inert. This seemed to confirm current understandings of women being unable to exercise self-determination and perform active citizenship. Fat became feminine. (Also when it was attached to men’s bodies: Fat men, some decades ago considered embodiments of economic success, were now increasingly regarded as effeminate.)

However, Peters’ book also challenged the linkage of fat and femininity. Her call to arms conveyed that “[w]omen evidently is not the weaker sex in a mental way,” as one reader of Peters’ book expressed it. Because slimming seemed to be something women were rather unable to do, the female fight against fat could symbolize an overcoming of the alleged inertia, the performance of self-restraint and—ultimately—a challenge of gender boundaries. Thus, despite the shadows of sexism and fatphobia that the early history of dieting cast, it was, paradoxically, also a history of female empowerment.