(informal)Food with little or no nutritional value; alternatively, food that supplies a large amount of nutrients but also excess calories, excess sugar or starch, and so on.
2012 June 17, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “Homer’s Triple Bypass” (season 4, episode 11; originally aired 12/17/1992)”, in The Onion AV Club[1]:
The episode begins with a lifetime of junk food, beer and no exercise catching up with Homer in the form of painful heart contractions.
2018, Timothy R. Jennings, The Aging Brain, →ISBN, page 82:
Junk foods and fast foods such as pizzas, hot dogs, doughnuts, cookies, cakes, and so on increase inflammation, promote insulin resistance, and increase the risk of diabetes and obesity.
