This book had a profound impact on the food industry. While Sinclair wrote The Jungle in 1906 order to build public sympathy for the plight of oppressed workers, he happened to set his story amid the meatpacking plants of Chicago. As a result, the novel set off a firestorm of protest about the lack of sanitation in the food industry. In the novel, anything, including human bodies, that happened to fall into the food vats were ground up and canned. At this time, there were no government inspections of meat plants and no real way for people to know what they were buying.
As a result of people's worry and revulsion after reading the book, which was a bestseller, meat sales fell. In 1906, the government passed the Pure Food and Drug Act and the Meat Inspection Act to reassure the public that they were buying what they thought they were buying. Government inspectors could now enter meat packing plants, inspect what was going on, and certify the products as safe for consumption. Sinclair famously said that he aimed for people's hearts in the novel and ended up hitting their stomachs.
Since the novel's publication, the public has supported regulation of the food industry so that people know what they are eating. Never again would the public trust the food industry to regulate itself wholly without oversight. This interest in food industry supervision has continued, so that now companies must list the ingredients in food and other nutritional information on food packaging.