The caloric overload wreaked havoc on the nation's collective digestive system. "Dyspepsia", The term coined for the ailment faced by many Americans, is exactly what made health advocates like Sylvester Graham and John Harvey Kellogg successful. According to them, Americans were overeating themselves until they were sick, and practitioners like Kellogg who advocated lighter diets found their patients miraculously cured. The predominant breakfast style of the time was very heavy, laden with meat and starch. Gerald Carson, in his book Cornflake Crusade, wrote in regards to the effects of the food on churchgoers that "the effects of such a heavy breakfast were so stupefying that the minister preached, in effect, to tons and tons of pork and beans." When vegetarian foods like Corn Flakes and Grape Nuts came on to the market purporting to cure the massive case of indigestion and food induced stupor faced by the country, they took the market by storm. Post, Kellogg, and the other more minor cereal companies all marketed their foods as health foods- aiding in the vitality of the consumer, curing diseases, and later, delicious to boot.
Postum marketed Grape Nuts as a dish that could fix almost any ailment, from appendicitis to loose teeth. Malaria and consumption (tuberculosis) were also reportedly cured by the consumption of Grape Nuts, and alleged endorsements by prominent physicians(who remained nameless in the advertisements) appeared in advertisements for the cereal. It was claimed to be a food especially good for the brain and central nervous system, and several advertisements was targeted towards parents, aiming to portray Grape Nuts as a food highly beneficial for the development of children. Advertisements for the cereal claimed that the human body gained more nutrition from Grape Nuts than any other known food, and the long baking process that the cereal underwent meant that the cereal was easier to digest. Ads for Grape Nuts began to claim that the food was "pre-digested". The Pure Food and Drug Act of 1906 helped to tone down medicinal claims in their advertising however, and advertisements began to center around the taste and purity of the food, along with less specifically medical claims that cereal was simply good for people- especially children- and it helped them grow and be healthy and strong. Like Postum, Kellogg's company made claims in their advertisements that their foods would have a medicinal effect on the consumer. Boxes of Granose Flakes, the first flake breakfast food produced and sold commercially by the Kelloggs, came with the slogan "Enrich the Blood". The Pure Food and Drug Act of 1906 helped put an end to their heavily medicinal claims exactly as it had with Postum and Kellogg's transitioned to marketing their foods with less medical claims. Advertisements that arrived after the Pure Food and Drug Act built instead on the vitality improving aspects of the food.