Harvard School of Public Health has a guide for the general pubic: https://www.hsph.harvard.edu/nutritionsource/processed-foods/ https://www.hsph.harvard.edu/n

Harvard School of Public Health has a guide for the general pubic: https://www.hsph.harvard.edu/nutritionsource/processed-foods/ https://www.hsph.harvard.edu/nutritionsource/processed-foods... Unprocessed or minimally processed foods Unprocessed foods include the natural edible food parts of plants and animals. Minimally processed foods have been slightly altered for the main purpose of preservation but which does not substantially change the nutritional content of the food. Examples include cleaning and removing inedible or unwanted parts, grinding, refrigeration, pasteurization, fermentation, freezing, and vacuum-packaging. This allows the food to be stored for a greater amount of time and remain safe to eat. Many fresh fruits, vegetables, whole grains, nuts, meats, and milk fall into this category. Processed culinary ingredients Food ingredients derived from a minimally processed food by pressing, refining, grinding, or milling. They are typically not eaten on their own but used to prepare minimally processed foods. Examples include oils from plants, seeds, and nuts, or flour and pastas formed from whole grains. Processed foods Foods from either of the two previous groups that have added salt, sugar, or fats. Some canned fruits and vegetables, some cheeses, freshly made bread, and canned fish are examples. These foods usually are made from at least 2-3 ingredients and can be readily eaten without further preparation. Ultra-processed foods Also commonly referred to as “highly processed foods,” these are foods from the prior group that go beyond the incorporation of salt, sweeteners, or fat to include artificial colors and flavors and preservatives that promote shelf stability, preserve texture, and increase palatability. Several processing steps using multiple ingredients comprise the ultra-processed food. It is speculated that these foods are designed to specifically increase cravings so that people will overeat them and purchase more. They are typically ready-to-eat with minimal additional preparation. Not all but some of these foods tend to be low in fiber and nutrients. Examples are sugary drinks, cookies, some crackers, chips, and breakfast cereals, some frozen dinners, and luncheon meats. These foods may partially if not completely replace minimally processed foods in some people’s diets. One study using data from the U.S. National Health and Nutrition Examination Survey found that ultra-processed foods comprised about 60% of total calories in the U.S. diet. [4] An association has been suggested between the increasing sales of ultra-processed foods and the rise in obesity. [3] My rule of thumb is that "processed food" is the food cooked in one's kitchen, made from base ingredients with added salt, fat or sugar. "Ultra processed food" is the stuff that is not normally made in a kitchen, but in a factory.