What Are Macronutrients? What They Do and Dietary Advice

Medically Reviewed By Maya Feller, MS, RD, CDN

Macronutrients are the nutrients that your body needs in the largest amounts. The three main macronutrients are carbohydrates, protein, and fat. We can gain all of these through our diet. Macronutrients help your body function, provide your body with energy, and even help with disease prevention.

A balanced diet includes all three macronutrients in their recommended quantities.

This article highlights the daily recommended intakes for each macronutrient and its purposes.

What are macronutrients?

A person holds two plates of spaghetti while a server adds more food with serving tongs.
Mattia/Stocksy United

Macronutrients are a group of nutrients that your body needs to function at its best.

Your body cannot make enough of these essential nutrients on its own, so it is necessary to consume them through food. 

Exact dietary needs will vary by individual. Factors such as age, sex assigned at birth, lifestyle, and preexisting conditions play a role in how much of each macronutrient a body needs.

A registered dietitian can help you determine how to distribute your energy intake from food between the macronutrients.

As a general guide, the United States Department of Agriculture (USDA) Trusted Source Dietary Guidelines for Americans (USDA) Governmental authority Go to source recommends that you get the following calorie percentages from each macronutrient: 

  • 45–65% from carbohydrates
  • 10–35% from protein
  • 20–35% from fat

What is the difference between macronutrients and micronutrients?

Micronutrients are another type of essential nutrient category. They include vitamins and minerals.

The main difference between macronutrients and micronutrients is the amount of each one we need for optimal health. While we need micronutrients in smaller quantities, macronutrients are necessary in large amounts.

Learn more about micronutrients and their role in nutrition.

Protein 

This macronutrient is a component of every cell in the human body.

Chemicals called amino acids make up proteins. Some of these amino acids are essential, whereas others are nonessential. Your body needs to obtain essential amino acids through food. Clinicians call them “essential” because our bodies cannot make essential amino acids on their own.

Although the body still needs nonessential amino acids, it can make some nonessential amino acids on its own by breaking down body proteins. Food is an additional source of nonessential amino acids

When we take in protein, the body breaks apart the amino acids in this protein to reuse them as building blocks and transmitters for bodily functions.

Protein is also a major energy source. 

Get more information about amino acids and their roles in the body.

Sources of protein

You can get protein into your diet by consuming animal-based and some plant-based foods.

Animal-based protein sources include: 

  • milk and other dairy products, such as cheese
  • eggs
  • seafood
  • poultry, such as chicken and turkey
  • red meats, such as beef, pork, and lamb

Sources of plant-based protein include: 

  • nuts and seeds
  • soy products
  • whole grains 
  • beans and legumes, such as chickpeas, lentils, and kidney beans
  • edamame
  • tempeh, tofu, and seitan

Always contact your doctor or a registered dietitian before increasing your protein intake.

Eating too much of certain protein sources, such as red meat, may increase your risk of heart disease. A 2019 study Trusted Source American Journal of Clinical Nutrition Peer reviewed journal Go to source indicates that long-term red meat consumption can increase the risk of a chemical link to heart disease. 

Most people Trusted Source Dietary Guidelines for Americans (USDA) Governmental authority Go to source in the United States get their recommended daily intake of protein, but not enough from the right sources. For example, some people eat more red meat sources of protein than the USDA recommends. These individuals also often eat less plant-based and lean sources of protein.

How much protein do I need?

The USDA recommends that 10–35% Trusted Source Dietary Guidelines for Americans (USDA) Governmental authority Go to source of your daily calories should come from protein.

However, the exact amount suitable for you will depend on certain factors, such as your sex assigned at birth, age, overall health, and lifestyle.

Carbohydrates 

Like proteins, carbohydrates are another major energy source. This means that they provide energy for the function of the body’s cells, tissues, and organs.

Your body breaks carbohydrates down into glucose for immediate use or storage.

Sources of carbohydrates

Plants are the primary carbohydrate source, though carbohydrates are also present in dairy products.

There are three main types of carbohydrates. These are as follows:

  • Sugars: This is the most basic form of carbohydrate, so clinicians often refer to them as “simple” carbohydrates. Naturally occurring carbohydrates are present in fruits, vegetables, and dairy. However, packaged or highly processed foods often contain added sugar. Added sugars differ from natural sugars and do not offer any essential nutrients.
  • Fiber: Fiber is a complex carbohydrate. As the body cannot break most fibers down, fiber can make you feel full for longer. High fiber diets can prevent constipation, lower cholesterol, and help maintain healthy blood sugar levels. Nuts, seeds, vegetables, fruits, beans, and whole grains are all excellent sources of fiber in the diet. 
  • Starches: Starches are also complex carbohydrates, meaning that they consist of many simple sugars strung together in chains. Some sources of starches include pasta, rice, bread, potatoes, and peas. 

You should aim to get the majority of your daily recommended carbohydrates from natural sources, such as fruits and vegetables, rather than from refined or added sugar and sweets. This is because consuming too much added sugar can lead to ill health.

The American Diabetes Association recommends that people with diabetes consume most of their carbohydrates from whole, minimally processed, and nonstarchy vegetables. 

The Food and Drug Administration (FDA) also suggests relying on whole grains such as brown rice, couscous, and quinoa as sources of carbohydrates rather than pasta and cereals made with refined whole grains. 

How many carbohydrates do I need?

According to the FDA, most people in the U.S. exceed their daily recommended intake of carbohydrates.

The USDA recommends that 45–65% Trusted Source Dietary Guidelines for Americans (USDA) Governmental authority Go to source of your daily calories come from carbohydrates.

Some people eat less than this amount of carbohydrates to maintain a moderate weight. However, a low carbohydrate diet may not be sustainable in the long term, and it is not the only way to reach and maintain a moderate weight. 

Always consult a registered clinician before starting a restrictive diet.

Fats

Fats play an important role in making you feel full, maintaining healthy skin and hair, and absorbing fat-soluble vitamins. Your body also uses fats for blood clotting and immune response.

Cell membranes contain fat, so you need this macronutrient for proper cell growth and development.

Sources of fats

There are several types of fats, and each kind has specific sources. These types are as follows:

  • Saturated fats: Animal fats, baked goods, dairy products, desserts, meat products, processed foods, and sweets all contain this type of fat. Plant oils and vegetable shortening also contain saturated fat. This fat type is usually solid at room temperature. 
  • Trans fats: This fat type occurs naturally in dairy and certain meat products. It also occurs in its processed form in baked goods, snack foods, and hydrogenated oils. It is present in smaller quantities in refined vegetable oils.
  • Unsaturated, or monounsaturated and polyunsaturated, fats: These fats occur naturally in olives, seeds, nuts, avocados, and fish. Mayonnaise, oil-based salad dressings, and vegetable oils also contain these fats.  

Diets that are high in trans fats and saturated fats can increase low-density lipoprotein, or “bad,” cholesterol. For this reason, you should aim to get most of your daily recommended fat intake through monounsaturated and polyunsaturated fats.

How much fat do I need?

According to the USDA, 20–35% Trusted Source Dietary Guidelines for Americans (USDA) Governmental authority Go to source of your daily calories should come from fat.

So, for example, someone following a 2,000-calorie-per-day diet should aim to limit their fat intake to about 78 grams per day

Additionally, the U.S. Department of Health and Human Services Trusted Source Department of Health and Human Services Governmental authority Go to source recommends limiting your saturated fat intake to less than 10% of your daily calories. 

Tips for meeting your dietary needs

In some cases, consuming too much of one macronutrient and not enough of others may lead to health issues, such as type 2 diabetes.

Using an app or online macronutrient calculator can help you estimate your current macronutrient intake and learn about your recommended nutrition intake levels per day. The USDA offers an online calculator to help you estimate your daily nutrient intake requirements.

However, some people may find macronutrient tracking and calorie counting to be triggering or distressing. If you are not comfortable with monitoring your food intake in this way, you can try using your hands to gauge portion sizes, according to the Centers for Disease Control and Prevention (CDC) Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source

Additionally, the USDA — with their nutrition program MyPlate — suggests the following advice to roughly monitor your nutrition without counting calories:

  • Aim to have vegetables or whole fruits take up half the plate with each meal.
  • Make half of your grain intake come from whole grain sources.
  • Reduce your food sources of added sugars, saturated fats, and sodium.
  • Include a wide variety of protein sources, including lean meats, seafood, and plant-based proteins.

Your doctor or a registered nutrition professional can also provide advice on nutrition and what is appropriate for you.

Summary

Macronutrients are the nutrients that your body requires in the largest amounts.

Protein, fat, and carbohydrates are the three main macronutrients. Your body uses macronutrients for energy sources and for daily functions.

Whole foods such as fish, poultry, fruits, vegetables, nuts, and seeds are healthy sources of macronutrients. The amount you need of each macronutrient varies based on your daily recommended intake of calories, which will also vary based on your age, sex assigned at birth, overall health, and lifestyle.

Contact your doctor or a registered nutrition professional for more advice on your individual nutritional needs.

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Medical Reviewer: Maya Feller, MS, RD, CDN
Last Review Date: 2022 Jun 27
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