"Empty calories" excessive sugar and fat and carbs usually cause that name to be designated to certain foods. 11/11/23

No real nutritional value.

Food, i.e. edible substances, that are high in fat and/or sugar, high in calories, often high in sodium, with poor balance of amino acids, poor vitamin content, poor mineral content (outside of sodium). This is moderately subjective.

Carbs and Sugar content in it

The ratio of nutritional value to fat and calories. * Of course, fat and calories are in and of themselves nutritional, but they are the most easily and most frequently over-indulged (i.e. consumed to a harmful degree). Junk food is typically high in fat and calories compared to the amount of other healthful nutrition (vitamins and minerals). *** For example: baked potatoes are very nutritious. (I love 'em with just salt and pepper.) Add butter and sour cream, and they are closer to being junk food...even though all of the nutrition that was in them before adding butter and sour cream was also in them after. Now consider french fries. Again: practically all of the nutrition that was in the potato originally is still in the french fries, and potatoes are very nutritious...but now there's so much fat and so many calories added to the potato that you're overindulging those things. *** So I guess the bottom line is: if eating a particular food as a "dietary staple" is likely to be harmful to your health, then that food is "junk food". Sweets - junk. Deep fried foods - junk. *** Some answers mentioned carbs - but of course certain types of carbs are very healthful and would never be considered "junk food". For example: whole grains and products made with 100% whole grains (like 100% wheat bread or brown Thai rice).

High calories and low nutritional values.