There are three main types of macronutrients (macros): proteins, fats, and carbohydrates. They are essential nutrients the body needs in large quantities to remain healthy.

Macronutrients provide the body with energy, help prevent disease, and allow the body to function correctly. Macronutrients are available in many food sources, but it can be difficult to determine the right amount to consume. There are also a number of factors that can influence the quantity of macronutrients people may need.

This article covers the importance of macronutrients in the body, different macronutrient diets, and how to incorporate macronutrients for a healthy diet.

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When it comes to nutrients, there are two main categories to consider: macronutrients and micronutrients. Macronutrients are nutrients that people regularly require in large quantities to provide their body with energy to perform bodily functions and daily activities.

Most often, macronutrients simply refer to proteins, carbohydrates, and fats, but some people may also include other nutrients that people require in large amounts, such as water.

Most of the body’s energy and calories come from macronutrients. Each type of macronutrient has its own benefits and purpose in maintaining a healthy body. The exact amount of each macronutrient a person requires may vary based on individual factors such as weight, age, and preexisting health conditions.

Each type of macronutrient performs an important role in keeping the body healthy. For optimum health, people typically require a balance of macronutrients.


Carbohydrates are a preferred source of energy for several body tissues, and the primary energy source for the brain. The body can break carbohydrates down into glucose, which moves from the bloodstream into the body’s cells and allows them to function.

Carbohydrates are important for muscle contraction during intense exercise. Even at rest, carbohydrates enable the body to perform vital functions such as maintaining body temperature, keeping the heart beating, and digesting food.

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Protein consists of long chains of compounds called amino acids. These play an essential role in the growth, development, repair, and maintenance of body tissues.

Protein is present in every body cell, and adequate protein intake is important for keeping the muscles, bones, and tissues healthy. Protein also plays a vital role in many bodily processes, such as aiding the immune system, biochemical reactions, and providing structure and support for cells.

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Fats are an important part of the diet that can also provide the body with energy. While some types of dietary fats may be healthier than others, they are an essential part of the diet and play a role in hormone production, cell growth, energy storage, and the absorption of important vitamins.

Click here to learn more about saturated and unsaturated fats.

The federal Acceptable Macronutrient Distribution Range suggests the following percentages of macronutrients for good health and to provide essential nutrition:

  • 45–65% carbohydrates
  • 20–35% fats
  • 10–35% protein

The Dietary Guidelines for Americans, 2020–2025 suggests similar values, but notes that people’s calories and macro requirements can vary due to factors such as age, sex, and whether they are pregnant. Additionally, other factors that can influence a person’s macro requirements can include:

  • current weight
  • fitness goals
  • existing health conditions
  • current muscle mass

While most foods contain a combination of macronutrients, some sources are better than others for specific macronutrients.

When considering a diet or nutrition plan, some people may try macro diets, which focus on the balance of macronutrients. Some examples of popular macro diets include:

Keto diet

The keto diet uses a low carb, adequate protein, and high fat approach that may help some people with weight loss. People on the keto diet cut their intake of carbs to less than 50 grams a day. With this very low intake, the body starts relying heavily on fats for energy production. This induces a state of ketosis, and may help with weight loss.

Paleo diet

The paleo diet mimics how people may have eaten during the Paleolithic era. It involves food that people could theoretically hunt or gather. While the macronutrients can vary in a paleo diet, they typically include higher levels of protein and fats and lower levels of carbs.

Weight Watchers diet

The Weight Watchers plan is a diet program involving a points system that restricts the amount and types of foods people may eat. It usually incorporates higher levels of protein, and encourages consuming less fats and carbohydrates with a high sugar content.

IIFYM diet

The IIFYM diet (IIFYM standing for “if it fits your macros”) involves focusing on macronutrients rather than just calories. Unlike other diets, which may involve food restrictions, the IIFYM diet is a flexible eating plan that focuses on tracking macronutrients to help achieve steady weight loss.

While macronutrients include fats, carbohydrates, and proteins, micronutrients (micros) refer to essential vitamins and minerals. The body needs both types to stay healthy and function correctly, but it requires more macronutrients than micronutrients. Experts measure macronutrients in grams (g), and micronutrients in milligrams (mg) or micrograms (mcg). This is due to people consuming micronutrients in smaller quantities.

Similar to macronutrients, a number of factors can influence the amount of micronutrients people require. People can use Dietary Reference Intakes to help guide how much they should consume. While people are often able to get sufficient levels of micronutrients from a healthy diet, some may need to take a multivitamin to meet recommended intakes.

Click here to learn more about micros vs. macros.

Macronutrients are essential nutrients that the body regularly requires in large amounts in order to function. They consist of proteins, carbohydrates, and fats. All three types of macronutrients play important roles in the body, and a healthy diet will typically supply sufficient amounts of each.

Macronutrients are different to micronutrients, such as vitamins and minerals, as the body requires them in larger quantities. A number of factors, such as age, sex, fitness goals, and preexisting health conditions can influence the amount of macronutrients a person requires. A doctor, nutritionist, or dietician can help guide people on their macro requirements, and suggest which diets may be beneficial.