Food has often been treated that as a status symbol. Being overweight was historically an indication of wealth. The poor could not afford much food, and were sometimes prohibited from certain foods.
Caligula famously threw a banquet once consisting of thousands of flamingo tongues, camel heels, and roast ostrich. Quoting from http://archive.archaeology.org/0111/abstracts/romans.html :
> Eating well was not just a daily ritual, it was a philosophy and a way of life in Imperial Rome. Your reputation and acceptance in the upper echelons of society was often determined by your abilities as a generous host and as a connoisseur.
"Healthy eating", as the essay observes, has a long history in the US. Kellogg started the Battle Creek Sanitarium in the 1860s. Quoting from http://en.wikipedia.org/wiki/Battle_Creek_Sanitarium, Kellogg "encouraged a low-fat, low-protein diet with an emphasis on whole grains, fiber-rich foods, and most importantly, nuts. Kellogg also recommended a daily intake of fresh air, exercise, and the importance of hygiene. Many of the theories of John Harvey Kellogg were later published in his book The Road to Wellness."
> Battle Creek utilised information as known at that time to provide nutritional requirements for health and well-being relative to each person's requirements. Food required careful prescriptive preparation, with care also taken to ensure appetiveness and palatability were recognised. The diet lists included "scores of special dishes and hundreds of special food preparations, each of which has been carefully studied in relation to its nutritive and therapeutic properties", with the diet lists used "by the physicians in arranging the diet prescriptions of individual patients".
You may know Kellogg better as the producer of corn flakes.
Diet was also used as social distinction. As a clear example, Italian Americans brought with them a love of garlic, which wasn't popular in the US. A xenophobic slur was to call someone of Italian food heritage a "garlic eater." See http://www.billszone.com/fanzone/archive/index.php/t-224620.... for an example:
> In 1960 "we had become truly one nation and one people"?!?!? Really??? You want to tell that to the millions of blacks under Jim Crow laws...government sanctioned institutional RACISM. Holy Jesus! Pat has now lost any semblance of that honesty I gave him.
> Then he distorts history, leaving out the rank "racism" that the Irish...German...Italians...Poles...Jews and "other Eastern Europeans" suffered when they came to this country. My God...I felt first hand the prejudice and rank hatred directed toward Italians we'll into the 80's. Most notably, by the father of a woman I was seeing. He was a WASP, and he left no doubt that my Italian heritage made me a low life. He derisively called me "garlic eater" and let it be known that his daughter was too good for a Dago like me.