Most cooked foods can be termed as 'processed foods', but ultra-processed foods are in a different domain, with few people having the clarity to differentiate.

A cooked carrot is processed food, but a bag of industrially-produced, carrot-flavored veggie puffs are ultra-processed and are still aimed at toddlers as a portion of natural food. Other examples include frozen peas or pasteurized milk.

Dr. Carlos Monteiro published a list of four different categories of food, according to how it is processed. This list, known as the Nova System, became a well-known guideline towards eating healthier:

• Unprocessed or minimally processed foods, like fruits and vegetables, a steak, and dry fruit,
• Processed culinary ingredients like butter, salt, sugar, oil, and flour.
• Processed foods like canned tomato juice, pickles, smoked fish, and traditionally-made bread.
• Ultra-processed foods like cereal bars, turkey hot dog, sausage rolls, Oreo cookies.

An extensive study in 2018 proved that an ultra-processed diet was responsible for substantial weight gain among participants, as well as 'hunger hormones' remaining activated even after eating.

As developing countries rely on cheap, tasty food to sustain themselves, ultra-processed food consumption is inevitable. However, this practice has to be regulated or reduced because the problem of nutrition cannot be cured by sophisticated processing.