On each of the decades you will find the prices of at least 20 food items for each decade

Food The Changes to Fast Food

Fast food has been designed to be eaten on the move and often do not require traditional cutlery. Common menu items at fast food outlets include fish and chips, Hotdogs, sandwiches, pitas, hamburgers, fried chicken, french fries, chicken nuggets, tacos, pizza, and ice cream.

Harry Ramsden's Fish n Chips 1928
Dairy Queen Ice cream 1940
Kentucky Fried Chicken KFC in 1952
McDonald's, the largest fast-food chain in the world did not appear until 1954
Burger King's first restaurant was opened in 1954
Wimpy 1954
Pizza Hut 1958
Domino's Pizza 1960
Taco Bell 1962
Subway sandwiches and salads 1965
Pizza Express 1965
Wendy's 1969
Potbelly Sandwich Works 1977
Fuddruckers 1980
Culver's 1984
Pret a Manger Sandwiches and salads 1986
Atlanta Bread Company 1993
One of the few posotives we can take from above is the growth in the Sandwiches and salad area in fast foods which does show more of us are at least trying to eat healthier even from fast food restaurants.

The other major growth area in our food consumption has been the convenience foods

Convenience foods or processed foods are designed to save consumers time in the kitchen, reduce costs due to spoilage, and reduce costs using economies of scale. They require minimum preparation, typically just heating, and are packaged for a long shelf life with little loss of flavour and nutrients over time.
They typically are high in fat and calorie contents, and preservatives are almost always used. In general the cost is very low and they are quick to prepare, and because many are frozen they can be kept for longer periods of time.
In 1965 only 25% of foods consumed were fast food or convenience food but currently this is much closer to 70% and the associated problems with obesity continues to increase