If you were inclined (which I suspect you aren’t) to look up the definition of food (noun, \ˈfüd\) in the on-line Merriam-Webster dictionary, you would get the following:
- material consisting essentially of protein, carbohydrate, and fat used in the body of an organism to sustain growth, repair, and vital processes and to furnish energy
- inorganic substances absorbed by plants in gaseous form or in water solution
I hate to say it, but… it’s kind of wrong! In fact, I’m a little bummed about how much really important information is missing from that definition! It should at least list all the different kinds of nutrients, instead of just a few. And don’t get me started on the definition of nutrient. (“Furnishing nourishment”… really?! That’s the best you can do?)
As it seems that even old Merriam and Webster are not sufficiently furthering our understanding of food, let me give you some basic definitions for the types of nutrients we need. I know, I know… definitions are so b-o-r-ing!!! But, in case my graph of an apple’s nutrients didn’t do this, I think these definitions will illustrate for you how beautifully complex our food really is!
Real food is so much more than just carbs, fat, and protein. There are all of these tiny little nutrients in our food, many of which are lost or destroyed in the process of taking a whole food and turning it into something not even loosely resembling the original. And because no one food has all of these nutrients, eating a widely varied diet is essential to get everything in that your body needs to thrive. Finally, recognizing all the different types of nutrients will give you a greater appreciation for just how much those -ion words must do for us in order to get all of the goodness out of the yummy things we put in our mouths.
So without further ado, these are the nominees in the category of “nutrients”…
- Macronutrient: these are the nutrients in our food that provide energy and the building blocks for all the cells of our body. “Macro” means large… which can either mean we need them in large amounts (relatively speaking), or that they are large and get broken down during digestion (either by us or by our wonderful gut microbiome). The subcategories include carbohydrates (which get broken down into monosaccharides), fats (which turn into glycerol and fatty acids), and protein (which is made of amino acids). In the photo above, you’ll notice that I separated fiber. Technically, fiber is a carbohydrate because of the types of molecules of which it is made. However, because humans do not have the enzymes to break down fiber into monosaccharides, it doesn’t contribute calories or cellular components the way other carbohydrates do. (In a future post, I’ll explain this more thoroughly.)
- Micronutrient: these are the vitamins and minerals that are found in small amounts in our food and of which we need small amounts (relatively speaking). There are 14 vitamins… well, really 14 groups of vitamins because there is more than one variety of some of them, like vitamins B6, D and K. For minerals, although there are 4,000+ known to exist in the world, only 21 are thought to be needed by humans. There are 3 major minerals, 7 essential trace and ultratrace minerals, and 7 nonessential trace and ultratrace minerals. (Before you ask, its really not necessary to know how much is required of an “ultratrace” mineral. 🙂 And see below for a definition of “essential.”)
- Phytonutrient: these are a large group of compounds found in plant foods that are thought to protect humans from disease and illness. They are a relatively new category of nutrient… so new, in fact, there aren’t even recommendations for how much of each of them we need! There are 12 categories, which include individual substances like quercetin (from apples), resveratrol (from grapes), catechins (from green tea), and hesperitin (from grapefruit). It’s the one set of nutrients for which there aren’t reference databases to tell you how much of each one is in each food, so it’s kind of hard to know that we’re getting enough of each one! A good rule of thumb, however, is that all minimally processed plant foods contain them (some of them get lost or destroyed with grinding, heating, drying, bleaching, etc) and the color of the food gives some indication of which types of phytonutrients are included. (If you are super interested in this, the amazing Dr. Deanna Minich has written whole books about the importance of phytonutrients!)
- Water: Even though it doesn’t seem like a nutrient… it is. In fact, it is our most essential nutrient… both from the technical definition (see below) and from the sheer fact that we can’t live without it. So as you are thinking about how you can ensure you are getting all the different types of nutrients… be sure you don’t forget about water!
Two additional notes…
As a side (but kind of critical) point, the word essential is used to describe any nutrient that humans cannot create themselves. For example, we cannot create the amino acid phenylalanine, so it is essential that we get it in the food we eat. However, if we have enough phenylalanine, our bodies can turn some of it into tyrosine, so it’s not essential that we get tyrosine from our food.
You may have noticed a section in the chart above called other. This is the additional stuff in the apple that are not considered nutrients. It is mainly made up of:
- The rest of the ash: Ash in food is the inorganic mineral content that is left when everything else is burned off. When classifying it in food, some of the ash is from minerals the body needs and some of it is not. The ash your body needs is classified in the minerals section, while the rest of it is listed as ash.
- The other tiny, but very important part is enzymes or coenzymes: Yes! Real food contains products that help you digest that food! In fact, raw milk that hasn’t been pasteurized to kill off microorganisms has lactase (the enzyme required to digest the lactose in milk). Pineapples and apples contain betaine which helps the liver as it handles all the food we eat. Papayas contain papain, an enzyme that digests protein. It works so well that papain is included in digestive enzyme supplements. Seriously… How cool is that our food helps us with the -ion words?!?
Now that you’ve gotten an overview of the different types of nutrients, don’t you agree with me that our food is amazingly complex?!
Tell me in the comments which nutrient you would give the prize to as your favorite… or which one you’d like to know more about.
— Boyer J, Liu RH. Apple phytochemicals and their health benefits. Nutr J. 2004;3(5),12.
— Gropper SS, Smith JL. Advanced Nutrition and Human Metabolism: 6th ed. Belmont, CA: Wadsworth Cengage Learning; 2013.
— Henneman K, Zidenberg-Cherr S. Some facts about phytochemicals. In Nutrition and Health Info Sheet for Health Professionals. Accessed March 3, 2015.
— McClements DJ. 4. Analysis of Ash and Minerals. Accessed March 3, 2015.
— Self. Apples, raw, with skin [Includes USDA commodity food A343]. In Nutrition Data. Accessed March 3, 2015.
— University of Maryland Medical Center. Betaine. Accessed March 4, 2015.