What's the Difference Between Macronutrients and Micronutrients?
Whether you're in a one-on-one session with a nutritionist or just doing some research online, odds are you've come across the words "macronutrients" and "micronutrients" quite a bit. (Perhaps even as much as seemingly everyone's favorite healthy-eating phrase, "balanced diet.") And while you might've nodded along as you read an article or listened to your R.D., odds are you could use a refresher (or even a beginner's course) on the topic. After all, you're only human (and not a trained pro yourself).
So, what are macronutrients? And what are micronutrients? Here, experts explain everything you need to know about the two and share specific examples of micronutrients and macronutrients.
What Are Macronutrients?
Macronutrients, aka "macros," are nutrients that you (and your body) need in large amounts, according to Nicole Roach, R.D., C.D.N., a registered dietitian at Lenox Hill Hospital. That's because macronutrients — which include carbohydrates, protein, and fat — provide energy in the form of calories. Carbohydrates and proteins both provide 4 calories per gram, while fat provides 9 calories per gram. So, the number of calories in a food actually describes the number of calories provided by the amount of each macronutrient in that dish. (BTW, fat, protein, and carbs are not just examples of macronutrients, but they're also three of the six essential nutrients.)
When digested in the body, macronutrients break down into smaller units, which support a myriad of functions vital to health such as muscle building and maintaining body temperature — in addition to, again, providing energy (via calories). Needless to say, macronutrients are a BFD. Oh, and because macronutrients are needed in such big quantities, they're measured in grams (vs. milligrams or micrograms, such as is the case for micronutrients).
Think of it this way: The macronutrients are like clothes, and your diet is like an outfit. Each macronutrient makes up a large portion of your diet, just like a shirt, jacket, or pair of pants would in an ensemble.
While fans of the continual low-carb craze might tell you otherwise, carbohydrates are not as evil as they're often made out to seem. In fact, this macronutrient can actually benefit your brain and body in many ways.
When digested, carbohydrates break down into a type of monosaccharide or sugar molecule known as glucose, which is the body's preferred (read: main) source of energy, says registered dietitian nutritionist Maya Feller, M.S., R.D., C.D.N. This is especially the case for the brain, which, according to Feller, "requires a consistent source of energy [from glucose] to function optimally." In fact, glucose is needed to produce neurotransmitters (chemical messengers), which are in charge of cognitive functions such as memory and thinking, according to a 2018 scientific review.
Carbs also keep the body's metabolic processes in check. Basically, if you don't get enough carbs (and, thus, glucose), your body will look for alternative energy sources, explains Feller. Muscle can be broken down to provide this energy, but over time, this can contribute to muscle loss, according to Oklahoma State University Extension. The good news: If you consume enough carbs, you can prevent your body from tapping into any of that hard-earned muscle for energy.
Point being: The body and brain are constantly using glucose, so a good chunk of your diet should be carbs in order to keep the glucose coming. In fact, out of all the macronutrients, the body typically needs the most calories from carbohydrates. More specifically, adults should get 45 to 65 percent of their daily calories from carbs, according to the United States Department of Agriculture's 2020 to 2025 Dietary Guidelines for Americans. (Read more: How Many Carbs Should You Eat Per Day?)
Up next on this list of macronutrient examples? Protein, which, ICYDK, is required to keep seemingly every part of the body running smoothly. Before getting into the specific functions of this powerhouse macronutrient, however, a little background info: Every protein molecule is made of compounds called amino acids, according to National Center for Biotechnology Information. And while the human body can make some amino acids on its own (called non-essential amino acids), it needs to get the others (essential amino acids) from food.
Aside from providing calories, protein (and the amino acids that it breaks down into) has several important functions in the body, such as transporting compounds within cells and supporting vital chemical reactions (e.g. producing energy), according to NCBI. Protein also provides structure to cells and tissues (e.g. muscles, organs). Altogether, without eating enough protein, the body will break down muscle mass, ultimately reducing strength and slowing down metabolic processes, says Feller.
Protein should make up 10 to 35 percent of your daily caloric intake, according to the 2020 to 2025 Dietary Guidelines for Americans. However, your exact requirements depend on factors such as your body weight, age, activity level, and overall health status. For example, according to NCBI, the daily recommended protein intake is 0.8 to 1 gram per kilogram of body weight (or 0.36 to 0.45 gram per pound of body weight) a day. And if you're physically active, that daily recommendation increases to 1.2 to 2 grams of protein per kilogram of body weight (or 0.54 to 0.9 grams of protein per pound of body weight). Why the boost? Because physical activity breaks down muscle tissue and protein is needed to repair it, according to the Academy of Nutrition and Dietetics. You'll also need more protein during pregnancy (to support fetal development) and after surgery (to support healing), notes Roach. In these scenarios, talk to your doc, who will consider other factors (such as your age, other medical conditions) to provide personalized guidance. (See also: What Eating the *Right* Amount of Protein Every Day Actually Looks Like)
Reminder: protein and carbohydrates each have 4 calories per gram, and fat contains 9 calories per gram, thereby making it the most energy-dense macronutrient, according to the NCBI. Unfortunately, however, it also tends to get a bad rap, which, in turn, leads many people to think that limiting fat is key for healthy eating — but that's not the case, explains Roach. "Fat is needed for energy, regulating body temperature, cushioning organs, and dispersing certain vitamins throughout the body," says Feller. Specifically, according to NCBI, the macronutrient is required for the absorption of fat-soluble vitamins, which include vitamins A, D, E, and K.
Though fat, in general, is needed in large amounts (it's a macronutrient after all), certain types of fats should be consumed in smaller quantities, says Roach. Saturated fat, which comes from dairy products, butter, red meat, pork, and tropical oils (palm/coconut), should generally be consumed in moderation, she notes. The same goes for trans fats, which are found in foods such as margarine and baked goods. Both saturated and trans fats are often considered "bad" because they can increase blood cholesterol, a major risk factor for heart disease, according to Harvard T.H. Chan School of Public Health. On the flip side, unsaturated fats are considered "good" and should be incorporated into the diet as much as possible. This includes omega-3 and omega-6 fatty acids, aka fats the body can't make but are required for good health, according to Oregon State University. You can find these bad boys in foods such as olive oil, nuts, seeds, and avocados, adds Roach. (Related: The Expert-Approved Guide to Good Fats vs. Bad Fats)
The 2020 to 2025 Dietary Guidelines for Americans recommend that adults get 20 to 35 percent of their daily calorie intake from fat. As noted above, saturated should be limited to smaller amounts — about 5 to 6 percent of your daily calories, according to American Heart Association.
Now that you know all about macronutrients, it's time to answer the question, "what are micronutrients?" The answer: Vitamin and minerals that the body needs in small amounts, says Feller. Unlike macronutrients, micronutrients do not provide energy via calories, but they aren't any less important. "Micronutrients are needed for every reaction that takes place in the body, [including] the digestion of food, muscle contractions, hormone production, and brain function, just to name a few," explains Feller.
ICYMI above, micronutrients are measured in milligrams or micrograms, unlike macronutrients, which, again, are measured in grams. The recommended intakes for micronutrients also aren't described as percentages of your daily calorie intake because, again, they don't provide energy. (Related: How to Read a Nutrition Label, According to Dietitians)
Let's take it back to that outfit analogy. Whereas macronutrients are the clothes in an outfit, micronutrients are akin to accessories. They naturally take up a smaller amount of the ensemble (read: your diet), but they're essential to creating a complete look, nonetheless. Without them, your overall diet would be incomplete and lack vital components.
There are 13 essential vitamins, which are categorized into two groups — fat-soluble and water-soluble vitamins — depending on the way they're absorbed in the body. Fat-soluble vitamins include vitamins A, D, E, and K, all of which need to dissolve in fat before the body can absorb them (see, fat truly is important!). Overall, fat-soluble vitamins — which are stored in fat tissue, liver, and muscles — support healthy immunity, bones, and vision, according to NCBI.
As for water-soluble vitamins? In the body, they need to dissolve in water in order to be absorbed, according to Harvard T.H. Chan School of Public Health. There are nine water-soluble vitamins: vitamin C — which supports immunity, wound healing, and collagen production — as well as eight types of B vitamins — which are necessary for producing energy and regulating metabolism.
These differences in solubility dictate how often you need each type of vitamin. Since fat-soluble vitamins can be stored in tissues, the body can hold on to them for a while, according to NCBI. (How long, exactly, depends on an array of factors, including liver health, fat and muscle content, and age, says Roach.) In contrast, because water-soluble vitamins dissolve in water, these nutrients are easily excreted through the urine, according to the National Library of Medicine.
Here are the recommended daily intakes for all 13 essential vitamins, according to NCBI.
- Vitamin A: 700 micrograms (women), 900 micrograms (men)
- Vitamin D: 10 to 15 micrograms
- Vitamin E: 15 milligrams
- Vitamin K: 90 micrograms (women), 120 micrograms (men)
- Vitamin C: 75 milligrams (women), 90 milligrams (men)
- Thiamine (B1): 1.1 milligrams (women), 1.2 milligrams (men)
- Riboflavin (B2): 1.1 milligrams (women), 1.3 milligrams (men)
- Niacin (B3): 14 milligrams (women), 16 milligrams (men)
- Pantothenic acid (B5): 5 milligrams
- Pyridoxine (B6): 1.3 milligrams
- Biotin (B7): 30 micrograms
- Folate (B9): 400 micrograms (800 micrograms for pregnant people)
- Cobalamin (B12): 2.4 micrograms
Another example of micronutrients, minerals are categorized into two groups based on how much you need. First, there are macrominerals, which are needed in doses larger than 100 milligrams per day, according to NCBI. This group includes potassium, sodium, calcium, magnesium, phosphorus, and chloride. And then there are microminerals, or trace minerals, which are required in doses less than 100 milligrams a day. These include selenium, iodine, iron, zinc, and copper.
But take note: Regardless of the amount needed, both types of minerals are essential. Minerals are just as important as macronutrients, explains Roach. "Just because we need them in small amounts does not make them any less significant," she says. Case in point: Minerals are necessary for a range of vital functions, including cell growth, blood pressure management, nerve function, and fluid balance, according to the NLM.
Below are the recommended intakes for adults, according to NCBI. (You can see how the recommended doses of the last five minerals, aka the microminerals, are smaller than the others on the list):
- Calcium: 1,200 milligrams (women), 1,000 milligrams (men)
- Phosphorous: 700 milligrams
- Magnesium: 400 milligrams
- Sodium: 1,500 milligrams
- Potassium: 4,700 milligrams
- Chloride: 1,500 milligrams
- Iron: 8 to 18 milligrams
- Copper: 1 milligram
- Zinc: 10 milligrams
- Selenium: 55 micrograms
- Iodine: 150 micrograms
How to Know You're Getting Enough Macronutrients and Micronutrients
Here's the thing: It's possible to track macronutrients, which some people may choose to do in order to hit certain health goals. However, counting macros requires a lot of mental energy. What's more, macronutrient recommendations are loose guidelines, which is why the intake ranges are so big. "Everyone needs different amounts of macronutrients," explains Roach. The exact amount you need on a daily basis is affected by age, sex, activity level, lifestyle, and medical conditions, she says. For example, as mentioned above, protein is needed for proper wound healing, so you'll likely need extra protein after a surgery or injury.
Meanwhile, micronutrients can be difficult to track, says Feller. That's because the micronutrient content of food can vary greatly, so accurately keeping tabs on your micronutrient consumption is nearly impossible — not to mention annoying AF.
The solution? Try not to overthink it. As long as you're eating a nutrient-dense and balanced diet — think: whole grains, fruits, vegetables, lean protein, and "good fats" — you'll meet your macro- and micronutrient needs, shares Feller. A registered dietitian can also provide guidance and help you determine what a balanced diet looks like for you. (See also: What Does a Nutritionist Do, Exactly?)