American eating changed dramatically in the early 20th century. As food production became more industrialized, nutritionists, home economists, and so-called racial scientists were all pointing Americans toward a new scientific diet approach. Food faddists were rewriting the most basic rules surrounding eating, while reformers were working to reshape the diets of immigrants and the poor. And by World War I, the country's first international aid program brought moral advice about food conservation into kitchens around the country.

In Modern Food, Moral Food, Helen Zoe Veit argues that a powerful conviction fueled the 20th-century food revolution that Americans had a moral obligation to use self-discipline and reason, rather than taste and tradition, in choosing what to eat.

Veit weaves together cultural history and the history of science to bring readers into the strange and complex world of the American Progressive Era. The era's emphasis on science and self-control left a profound mark on American eating, which remains today in everything from the ubiquity of science-based dietary advice to the tenacious idealization of thinness.