Show By Lizzie Streit, MS, RDN, LD on November 1, 2021 — Medically reviewed by Amy Richter, RD, Nutrition Macronutrients are a group of nutrients that provide your body with energy and the components it needs to maintain its structure and functions. Macronutrients include carbohydrates, protein, and fat. They’re needed in relatively larger amounts than other nutrients, hence the term “macro.” Although there are recommended ranges for macronutrient intake, your needs vary based on your personal circumstances. This article reviews the main macronutrients, food sources, functions, and how to assess your macro needs.
Macronutrients are nutrients that your body needs in large amounts to function optimally. The three main macronutrients are carbohydrates, protein, and fat. They’re considered essential nutrients, meaning your body either cannot make them or cannot make enough of them (1). For example, proteins provide essential amino acids, while fats contain essential fatty acids. Your body utilizes these components for specific functions (2). Macronutrients also contain energy in the form of calories. Carbs are the main energy source, but your body can use other macronutrients for energy if needed (3). The calorie content of each macronutrient is (4):
Summary You can obtain macronutrients from the foods you eat. It’s important to eat a variety of foods to get enough of each macronutrient. Most foods contain a combination of carbs, protein, and fat. Some foods are high in one specific macronutrient, while other foods contain high amounts of two nutrients and fall into two macronutrient groups. Sources of carbs include:
Sources of protein include:
Sources of fat include:
Summary Each macronutrient has specific functions in your body. During digestion, they’re broken down into smaller parts. These parts are then used for bodily functions like energy production, muscle building, and giving structure to cells. CarbsMost carbs are broken down into glucose, or sugar molecules. This doesn’t apply to dietary fiber, a type of carbohydrate that isn’t broken down and passes through your body undigested. Still, some fiber is fermented by bacteria in your colon (3, 5). Some of the main functions of carbs include (3, 5):
ProteinsProteins are digested into amino acids. Twenty amino acids have important functions in your body, 9 of which are essential and must be obtained from foods (5, 6). Some of the main uses of amino acids from protein include (5, 6):
FatsFats are broken down into fatty acids and glycerol (5, 7). Some of the main functions of lipids, or fats, include (5, 7):
Summary Macronutrients are different from micronutrients, which include vitamins and minerals. First, macronutrients are needed in relatively larger amounts than micronutrients. However, that doesn’t mean that micronutrients are less important. Micronutrients serve different roles in your body than macronutrients. There are 13 essential vitamins and 13 essential minerals, each of which has specific, sometimes overlapping functions. As a reminder, essential means that you have to get those nutrients from your diet. Some vitamins — D, K, B12, and biotin — can be produced by your body, but not always in adequate amounts. Micronutrients support growth, brain development, immune function, and energy metabolism (8). While macronutrients provide energy and are the building blocks of your body’s structure and functions, micronutrients don’t contain calories. Instead, they’re vital for extracting energy from food and facilitating most bodily processes (8). Summary Each macronutrient is incredibly important for your body to function optimally. It’s crucial that you get enough carbs, protein, and fat by eating a balanced diet comprising a variety of foods. Specifically, the United States Department of Agriculture (USDA) Dietary Guidelines recommend these Acceptable Macronutrient Distribution Ranges (AMDR) for adults (9):
The guidelines also recommend that adults get at least 130 grams of carbs per day. This is the Recommended Dietary Allowance (RDA) and considered the amount necessary to provide your brain with enough glucose (9). If there isn’t enough glucose available — which can happen if you’re following a strict keto diet or have issues regulating your insulin levels due to conditions like diabetes — your body is able to get energy by breaking down fat and protein. When it comes to protein, the RDA for adults is at least 0.36 grams per pound (0.8 grams per kg) of body weight (10). Keep in mind, though, that the appropriate amount of macronutrients for each person varies based on their age, activity levels, sex, and other circumstances. For example, children and adolescents may need more calories from fat than adults do for proper brain development (9). Older adults, on the other hand, need more protein to preserve muscle mass. Many experts recommend a protein intake of at least 0.45–0.54 grams per pound (1.0–1.2 grams per kg) for adults over the age of 65 (11). Athletes and highly active people often need more carbs and protein than those who are less active. They should aim for the higher end of the recommended ranges. Extra protein supports muscle building after exercise, while carbs provide calories to replenish energy stores. If you’re trying to lose weight, you might benefit from eating slightly below the recommended range of calories from carbs and above the range recommended for protein. Extra protein can help you feel full, while fewer carbs can promote a calorie deficit (12). Summary Counting macros is an increasingly popular tactic for people interested in losing weight. Some athletes or individuals who need specific amounts of a certain macro, such as protein for muscle building, also use this strategy. It usually involves coming up with a goal percentage of calories from each macro group and planning your meals accordingly. While macro counting can be an effective way for some people to reach their goals, it’s not necessary for everyone. In fact, if you eat a well-balanced diet with sources of each macronutrient, you likely meet the recommended intakes. For example, simply building a balanced plate at each meal is a great way to ensure that you get enough carbs, proteins, and fats. A rule of thumb is to fill about half of your plate with non-starchy vegetables, a quarter with high fiber carbs like fruit or whole grains, and the last quarter with a source of protein. Also, prioritize using healthy fats when cooking. If you’re interested in further assessing your macronutrient intake, consider working with a registered dietitian to help you figure out and meet your needs. Remember, the quality of the macros in your diet is more important than meeting a set amount every day. For example, if you eat sugary treats and refined carbs to meet your daily carb goal, you won’t get nearly as many nutrients and fiber as you would by eating fruits, veggies, and whole grains. Summary Macronutrients include carbs, protein, and fat. They provide energy and support bodily functions and structure. Current guidelines recommend that you get 45–65% of your daily calories from carbs, 10–35% from protein, and 20–35% from fat. However, individual needs vary. To ensure you get enough macronutrients from food, eat a balanced diet with sources of carbs, protein, and fat at every meal. Last medically reviewed on November 1, 2021 |