Industrial Foods include 'Processed Foods' which is not a well defined term but we all have some idea of what it means. For example, cans and jars of fully cooked or partially cooked foods with long lists of chemical ingredients are clearly Processed Foods. For details, see

A large number of contemporary books and documentaries describe the dangers of Processed Foods. For example, Salt Sugar Fat: How the Food Giants Hooked Us (480 pages, 2014) by Michael Moss is a New York Times Bestseller that traces the history of Processed Foods over the last 50 years. In Defense of Food (330 pages, 2009) by Michael Pollan is another NYTimes bestseller. This book offers interesting insights by tracing the history of Processed Foods over a longer time horizon (about 150 years).

It may also help to browse through Salt, Fat and Sugar Reduction (346 pages, 2020) which explains the mindset, approach and struggles of the Processed Foods industry to prepare meals with low/no salt, low/no fat and low/no sugar.

Animal Products include Meats, Fish & Dairy Products (Milk &Eggs).

• The word 'Meats' includes flesh of animals and birds, both. However, we use 'Animal Products' as the name of the category. Why? In nutrition literature, all meats are collectively called 'animal products', a term that does not distinguish between animals and birds.
• Some people may be suprised to see Dairy Products listed under Animal Products but that's how it is! Dairy (Milk & Eggs) comes from animals. Whole Food Plant-Based (WFPB) doctors explain that the protein structures found in dairy are similar to protein structures found in human bodies — this similarity plays a role in triggering autoimmune via the Leaky Gut & Molecular Mimicry.

SOS Extracts include Salt, Oils & Sugar.

• 'Salt' includes not only table salt but all kinds of salt including Himalayan salt, Celtic salt, red salt, and so on.
• 'Oil' includes all sorts of oils — both industrially processed and ancient, cold-pressed oils. Some diets don't eliminate oils but remove industrially processed oils and avoid certain cooking techniques like frying.
• 'Sugar' includes refined sugar.
• Dozens of other extracts are sold in the market. In this article, they are ignored them because diets and fasts emphasize only these three extracts; they ask us to either retain / eliminate one or more of them; other extracts are usually not discussed.

Broadly speaking, food sources from plants may be categorized into two:

• Pre-Agriculture: Vegetables, Fruits, Nuts & Seeds, Herbs & Spices. These foods were consumed by our ancestors who followed a hunter-gatherer lifestyle. Such a lifestyle continues to be followed by a very small number of people worldwide today.
• Foods introduced by agriculture: Grains, Beans & Legumes fall in this category. Additionally, agriculture introduced 'selective breeding' through which we have transformed even Pre-Agriculture plant foods (and animal foods) significantly.

For details, see Part 4: Pre-Agriculture, Agriculture & Modern Food Sources.

Liquids includes Juices, Teas & Broths, Water.

• The liquids listed above are commonly employed in various fasting regimens. Since our goal is to develop a broad understanding of various diets and fasts, we have chosen to ignore dozens of other liquids like alcoholic beverages, fermented drinks like kambucha, caffeinated drinks like coffee, and so on.

Under Modern Life are listed Supplements. The best known guidelines in the Whole Food Plant-Based (WFPB) community are by Dr Greger. See Optimum Nutrition Guidelines (2011; updated in 2017). Apart from supplements listed here, WFPB doctors generally recommend staying away from supplements. See Supplements by John McDougall (Youtube vidoes).

• Fungii, Algae, Bacteria and Rocks! Collectively, we consume many foods that do not belong to any of the categories above. Examples include fungii (mushrooms), algae (sea vegetables like nori and kelp), bacteria (in fermented foods), rocks (via rock salt), and so on.
• Overlapping categories: The categories listed above are not disjoint; there are some overlaps. For example, Juices, Teas and Broths can be derived from both animal and plant sources but they are placed in a separate category called Liquids. Similarly, All three SOS Extracts (Salt, Oil, Sugar) could be classified as Processed Foods but are listed separately.

  The goal in this article is not to form an accurate taxonomy of all foods but to grasp the big picture of diets and fasts listed in these articles: Part 1: Spectrum of Diets and Part 2: Raw Foods and Fasting Protocols. For that purpose, overlapping categories are okay.

• Real Foods vs Invisible Substances: Note that the 7 food categories above center around real foods (that can be seen, smelt, touched and tasted) instead of a long list of invisible substances like 'proteins' and 'amino acids' and 'simple carbohydrates' and 'complex carbohydrates' and 'unsaturated fats' and 'saturated fats' and 'vitamins' and 'antioxidants' and 'micronutrients' and 'phytonutrients' and …

  One of the chapters in Michael Pollan's book In Defense of Food (330 pages, 2009) traces the history of how the US Surgeon General's guidelines changed from real foods to invisible substances in 1950s. That event spawned an entire industry of 'nutritionists' who strive to identify combinations of foods that a specific individual (typically, a client of a nutritionist) or classes of individuals (say, diabetic patients in general) should eat to get the recommended daily allowances of invisible substances. Conceptually, this is a fascinating approach! … but is it effective?

  Turns out that food guidelines in terms of invisible substances introduce a lot of confusion! Especially in the minds of laypersons. See Interview with Dr Garth Davis (at offset 3:45) to get a glimpse into problems spawned by breaking down foods into its constituents and issuing food guidelines in terms of these constituents.

  Luckily, various diets and fasts can be understood in terms of real foods, not invisible substances!