For the privileged eaters of the Western world, so much of eating is done routinely: cereal for breakfast, a sandwich for lunch, probably a protein and vegetable for dinner. Sometimes, the act of eating is so second nature that the guidelines that dictate how and when we eat are invisible—guidelines such as eating a steak for dinner but not for breakfast, or eating lunch in the middle of the day. Eating wasn’t always dictated by these rules—so why is it now? That’s the question that food historian Abigail Carroll set out to answer in her new book, Three Squares: The Invention of the American Meal . Tracing the meal’s history from colonial America to present-day, Carroll explores why we eat cereal for breakfast, how dinner became American and how revisiting the history of our meal can have a tpositive impact on the future of eating. Carroll spoke with Smithsonian.com about the guidelines that control our dining.

How did the associations between certain meals and certain foods, like cereal for breakfast, form?

You start in the very early colonial era with one meal in the middle of the day—and it’s the hot meal of the day, dinner. Farmers and laborers ate earlier because they were up really early, and the elite were eating later in the day because they could sleep in. Breakfast and supper were kind of like glorified snacks, often leftovers or cornmeal mush, and there was not a lot of emphasis placed on these meals. Dinner, the main meal, at which people did tend to sit down together and eat, was really not the kind of social event that it has become. People did not emphasize manners, they did not emphasize conversation, and if conversation did take place it wasn’t very formal: it was really about eating and refueling. That’s the time where there are very blurry lines between what is and what isn’t a meal, and very blurry lines between what is breakfast, dinner and lunch.

Then, with the Industrial Revolution, everything changed, because people’s work schedules changed drastically. People were moving from the agrarian lifestyle to an urban, factory-driven lifestyle, and weren’t able to go home in the middle of the day. Instead, they could all come home and have dinner together, so that meal becomes special. And that’s when manners become very important, and protocol and formality. It’s really around then that people start to associate specific foods with certain meals.

Then, with dinner shifting you have the vacuum in the middle of the day that lunch is invented to fill. People are bringing pie for lunch, they’re bringing biscuits, but the sandwich really lends itself to lunch well. So the popularity of the sandwich really does have something to do with the rise of lunch—and especially the rise of children’s lunch, because it’s not messy. You don’t need utensils, you don’t have to clean up—you can stick it in a lunch pail really easily.

Why is it acceptable to eat cereal and eggs and a waffle for breakfast, but not for lunch or dinner? How did breakfast go from being a necessity meal—fueled by leftovers—to a meal with clear guidelines for what is acceptable to eat?

There was a problem during the Industrial Revolution: people were still eating a farmer’s diet, but they were shifting to a more sedentary lifestyle, which caused indigestion. People who were interested in health started looking into that and started coming up with solutions. Sylvester Graham, the reformer who became a preacher of health ideology, advocated for vegetarian food, and whole wheat as kind of a panacea for health problems, which becomes the answer to the question of breakfast. Then, people who ran sanitariums, including John Harvey Kellogg, in the late 1800s and early 1900s, really took that idea and flew with it and invented new ways to eat farinaceous foods.

Entrepreneurs—some of whom worked in the sanitariums, like Charles C. Post–really build on these ideas and make them a healthy requirement. He creates all sorts of crazy testimonies that serve as advertisements for Grape-Nuts, where people’s lives are saved from chronic illness and they’re able to walk again.

Then, there’s also the history of orange juice and milk, with the discovery of vitamins in the 1910s. Milk came to be seen as a super food, and something that would keep you from getting deficiency diseases. It shows up at other meals too, but for much of the 20th century, it’s not a complete meal unless you have milk.

Why is it that, in America, we have maintained the feeling that lunch needs to be a quick meal in the middle of the day?

We still are working a lot—we’re working more hours in the United States than any other industrialized nation. Lunch is the original quick meal; it accommodated changing work schedules.

And dinner has taken on the ideological weight of the meal. Dinner has been the time when we celebrate family, and when we concentrate on having a nice, hot meal, ideally. Because dinner fulfilled that need, there was less of a need for the other meals to. Lunch doesn’t have a lot of cultural work to do; it just has to get us by.

But, if you think about it, it’s not just lunch—it’s breakfast too. We can just pour milk over cereal, or pop some toast in the toaster and walk out the door without even needing a plate or utensils. Breakfast accommodates work. It’s not the meal that shapes work, it’s the work that shapes the meal.

Could you talk about how dinner became a particularly American institution?

Dinner was not initially a strong identifying factor, in terms of nationality, for colonists. At first, they were eating more or less peasant food, porridges brought from England that said more about class than nationality. Then, dinner shifts in the 1700s to become an identifying factor in terms of being English. They’re in this new world, seen as primitive, and so they feel that they have to compensate for that. They inherit the fashions that cross the ocean, like eating a roast with dinner.

In the nineteenth century, the emerging middle class identifies itself through French food and French ways of eating. Things that we take for granted now, like starting a meal with soup or having a salad, were really French concepts. Dessert was largely a French concept, and many of the desserts that we adopted in the 19th century were French desserts. For the Victorian middle class, eating in the French way was a way to imitate the elite.

With the decline of servants in the late 1800s, people just couldn’t keep that up. Then there are the Wars and the Depression, and those require Americans to be frugal. But they don’t just require Americans to be frugal—they give Americans the opportunity to celebrate frugality as patriotic. To eat frugally, to have a Victory Garden and can your own foods is patriotic. The model for dinner is no longer the French multicourse formal meal, but Thanksgiving. Thanksgiving becomes the model for the everyday American dinner. Of course, you don’t eat a whole roast every night, but the idea is that you have “a chicken in every pot,” which was Herbert Hoover’s 1928 campaign slogan. You would have some kind of meat on the table.

Are there any dishes or foods that you would classify as typically, or even exclusively, “American?”

A number of iconic foods—hot dogs and hamburgers, snack food—are hand-held. They’re novelties associated with entertainment. These are the kinds of food you eat at the ballpark, buy at a fair and eventually eat in your home. I think that there is a pattern there of iconic foods being quick and hand-held that speaks to the pace of American life, and also speaks to freedom. You’re free from the injunctions of Victorian manners and having to eat with a fork and knife and hold them properly, sit at the table and sit up straight and have your napkin properly placed. These foods shirk all that. There’s a sense of independence and a celebration of childhood in some of those foods, and we value that informality, the freedom and the fun that is associated with them.

Along those lines, there’s a lot of pushback against those processed foods today, with people wanting to recall old ways of eating, with eating local and fresh. But, how do you think that knowing the kinds of food that we used to eat and the ways that we used to eat, and think about eating, influences the future of American food?

History can play a really central role in thinking about the way that we want to eat in the future. The evolution of the meal is a process, and it continues.

With all of the talk of food and health, I think a really good question to ask is “Can we actually be healthy without eating meals?” And without even, perhaps, eating a family dinner? Studies show that eating together, we always eat better, always.

The family meal is the opportunity to put to work what we’re talking about. If we’re learning about fresh foods and ingredients, the family meal has potential to be another way of instructing our children and ourselves. There’s an interest in renewing the family meal, even reinventing it. We’re not going to be able to revive a Victorian notion of dining; I don’t think we’re interested in it. If we want to spend time together, if we want to invest in our children, if we want to be healthy, the family meal can be a vehicle for that.