Nutrition can get complex. Even a simple topic, like the difference between micronutrients and macronutrients, can be confusing. Thankfully, it doesn’t have to be!
Just remember: micro means small, and macro means big. Thus, macronutrients are the big energy-rich nutrients, whereas micronutrients are the small functional nutrients.
Let’s take a look at each of these and the subtypes of both micro and macronutrients.
Macronutrients are where we get the energy out of our diet. These are the big rocks: proteins, carbs, fats. They’re also big in that we eat a lot more of them. If you read nutritional labels, macronutrients are always measured in grams. Micronutrients, as we’ll see below, are measured in milligrams or sometimes just percentages.
Macronutrients are the source of all our calories. Eating the right balance of carbohydrates, proteins, and fats is important. Also included in macronutrients is fiber. Fiber is a subclass of carbohydrate that provides no energy.
Carbs are one of our primary sources of dietary energy. There are three types of carbohydrates: simple sugars, complex sugars, and dietary fiber.
Simple sugars, often just called sugars, are very easily digestible. They enter the bloodstream rapidly and provide us with energy immediately. According to the American Heart Association, you should limit your intake of sugar to 150 calories.1 Eating too many foods high in sugar can cause rapid changes to your blood sugar. Over time, this can contribute to type two diabetes.
Complex sugars, usually just called carbs or carbohydrates, also provide us with energy, but much more slowly. Complex carbs are not as easily digestible as simple sugars. It takes the body longer to digest complex carbohydrates. Thus, carbs provide energy over time. Like sugar, an excess of carbs can contribute to type two diabetes and weight gain.
Finally, dietary fiber is the most complex kind of carbohydrate. Fiber can sometimes be thought of as very complex sugars. So complex that our bodies cannot digest them. Fiber provides no energy but serves an important role in digestive health. I’m sure I don’t have to tell you just how fiber improves your digestive health. But more is usually better. The average American eats only 50% of their recommended daily fiber.2
Protein is another source of energy for our bodies. However, protein serves another role in nutrition. Proteins from the diet can be broken down into amino acids. Amino acids can then be rebuilt into human proteins that help perform all of the body’s functions. Approximately half of all dietary protein is used as energy, and the other half is used to build new proteins.3
Fats are the last macronutrient. Fats are an incredibly dense form of energy. Contrary to the name, fats don’t necessarily make you fat. While the Cleveland Clinic recommends limiting your daily intake of fat, you should still consume some fat.4
Micronutrients are very different from macronutrients. Micronutrients are vitamins and minerals that we need to survive. Unlike macronutrients, we only need very small quantities of micronutrients. Hence, the name micro, which means small.
We only need milligrams of most micronutrients every day. Some micronutrients are measured in micrograms. These amounts are so small that most nutritional labels simply give the percentage of the recommended daily value.
Vitamins are substances that play a diverse and important role in health. They aid in all aspects of health. Vitamins are necessary for nearly every biological function.
Vitamins are made by other living organisms. Many vitamins are found in plants, though some can be obtained from meat. However, humans cannot synthesize these on our own. Thus, we must get all our vitamins through diet.
Vitamins aid in growth and development of children as well as metabolism in children and adults. They help with proper immune function5 and maintaining healthy skin.6 Some vitamins are involved in the absorption of other micronutrients (notably, minerals), and many are required for the synthesis of specific proteins. All vitamins are essential, and deficiencies can cause serious health problems.
Minerals are similar to vitamins in that they are important for health. Like vitamins, they are involved in most bodily functions. Minerals are diverse in their chemical properties and their functions. They also tend to be needed in only very small quantities.
Unlike vitamins, minerals are very small substances. Often, they are individual elements (e.g., calcium). Our bodies use minerals in a variety of ways: some are incorporated into existing proteins or DNA, others in the balance of pH and ionic content of the body. Some are cofactors in biological reactions (i.e., they help catalyze a chemical change). Again, deficiencies in minerals can lead to very serious health problems.
- How much sugar is too much? The American Heart Association. https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/sugar/how-much-sugar-is-too-much. Accessed 7/29/2020.
- Increasing fiber intake. University of California San Francisco Health. https://www.ucsfhealth.org/education/increasing-fiber-intake#:~:text=The%20American%20Heart%20Association%20Eating,about%2015%20grams%20a%20day. Accessed 7/29/2020.
- Balancing carbs, proteins, and fat. Kaiser Permanente. https://wa.kaiserpermanente.org/healthAndWellness?item=%2Fcommon%2FhealthAndWellness%2Fconditions%2Fdiabetes%2FfoodBalancing.html. Accessed June 13, 2020.
- Fat: What you need to know. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/11208-fat-what-you-need-to-know#:~:text=type%20of%20fat.-,Total%20fat,because%20they%20provide%20health%20benefits. Accessed 7/29/2020.
- Feigen GA, Smith BH, Dix CE, et al. Enhancement of antibody production and protection against systemic anaphylaxis by large doses of vitamin C. J Urol. 1983;129(5):1091-1092. DOI: 10.1016/S0022-5347(17)52586-0.
- Fiedor J, Burda K. Potential role of carotenoids as antioxidants in human health and disease. Nutrients. 2014;6(2):466–488. DOI: 10.3390/nu6020466.