"Junk food" is a term used to describe food that is high in calories from macronutrients such as sugar and/or fat, and possibly sodium, making it hyperpalatable, but with insufficient dietary fiber, protein, or micronutrients such as vitamins and minerals. It is also known as HFSS food. The term junk food is a pejorative dating back to the 1950s. Many variations of junk food can be easily found in most supermarkets and fast food restaurants. Due to easy accessibility, commercially-oriented packaging, and often-low prices, people are most likely to consume it.

Fast food is a type of mass-produced food designed for commercial resale, with a strong priority placed on speed of service. It is a commercial term, limited to food sold in a restaurant or store with frozen, preheated or precooked ingredients and served in packaging for take-out/takeaway. Fast food was created as a commercial strategy to accommodate large numbers of busy commuters, travelers and wage workers. In 2018, the fast food industry was worth an estimated $570 billion globally.