Macronutrients are defined as chemical substances required in large amounts by the body for survival. The three macronutrients are protein, carbohydrates, and fats. If you’ve heard anyone talking about "macros," they’re referring to these critical nutrients. Some people also call alcohol a macronutrient, since it is processed differently from carbs, fats, and proteins. Of course, alcohol is not one of the three major classes of substances the body requires in large amounts – despite what some college students may think. But it’s the only other substance people consume in relatively large amounts.
The amounts of different macronutrients a person needs – as well as the ratio of nutrients to each other – varies by age, lifestyle (sedentary, active, or very active), gender, health status, and health goals.
Types of Macronutrients
The USDA provides general recommendations for how Americans should allocate calories (kcal) per macronutrient. The nutrition facts label included on food packaging echoes these recommendations and is based on a 2,000-calorie diet for the average American.
A calorie is a unit of measurement that counts the energy contained in food. If something contains 100 calories, your body uses 100 calories of energy to metabolize it. Each person has their own basal metabolic rate, which is how much energy or how many calories your body needs simply to stay alive. A rough calculation for your basal metabolic rate is your body weight multiplied by 11 for men and by 10 for women. Any exercise or movement is added to this basal metabolic rate. The macronutrients – plus alcohol – that you consume require additional energy for your body to burn or metabolize.
Many diets work by having you alter the ratio of macronutrients you consume to produce certain results. For example, consuming protein (along with weight training) might help you gain muscle mass, while consuming fewer carbohydrates can encourage weight loss.
Calories per Macronutrient
- 9 calories per gram of fat
- 4 calories per gram of protein
- 4 calories per gram of carbohydrates
- 7 calories per gram of alcohol
These are average values, since proteins, carbohydrates, and fats may vary slightly.
What About Alcohol?
Alcohol (ethanol) is a commonly consumed substance that contains seven calories per gram. Although some nutritionists are calling it a macronutrient, according to biologists, it is not a macronutrient because it is not "required in large quantities" for the body’s survival and functioning. It can be considered a nutrient, but not a macronutrient, as it does not provide any nutritional value to your diet. Although it’s commonly mentioned in conversation that consuming moderate amounts of alcohol can provide certain health benefits, there’s also a mountain of evidence to suggest that avoiding alcohol is the most health-conscious choice.
Alcohol does not stay in the body but is removed from the body by the alcohol dehydrogenase enzyme in the liver. Until alcohol is completely metabolized in the liver, it remains present in breath and in urine, which is why police can detect alcohol with a breathalyzer test.
What Are Carbohydrates?
Carbohydrates include starches, sugars, and fiber. Carbohydrates contain, on average, four calories per gram. Your body uses carbohydrates to fuel your body. Carbohydrates come in two forms: complex and simple. Simple carbohydrates include sugars like table sugar and high fructose corn syrup, which have one or two sugar molecules (mono- and disaccharides). Honey and maple syrup contain simple sugars, as well as other nutrients.
Complex carbohydrates are long chains of simple sugars stuck together, also called polysaccharides. They can be either starches or fiber (cellulose from plants). Foods like whole wheat pasta and white potatoes contain complex carbohydrates.
How Many Carbohydrates Do You Need?
Adults should get between 45-65% of their daily calories from carbohydrates.
According to the United States Department of Agriculture (USDA), American adults should get between 45-65% of their daily calories from carbohydrates.
Humans don’t produce the enzymes necessary to digest fiber, but it’s nonetheless required by the body. Your microbiota breaks down fiber by fermenting it and using it as their energy source. Your health relies on a balanced, well-nourished microbial gut community for many different functions, so make sure you get plenty of fiber-rich foods in your diet every day.
Sources of Carbohydrates
The best carbohydrates are micronutrient-dense whole foods that contain sugars or starches along with fiber. This definition leaves no room for confusion about whole fruit, which is considered a simple carbohydrate under some definitions. Fruit is an essential part of a healthy diet, and 76% of Americans don’t eat enough. Other excellent sources of carbohydrates include winter squash, beans, and ancient grains like quinoa.
What Is Protein?
Protein is the building block responsible for the growth and maintenance of your eyes, skin, hair, nails, organs, and muscle tissue. During digestion, protein is broken down into smaller chains called polypeptides and individual units called amino acids for absorption. Of the 22 amino acids that make up proteins, nine are called "essential" amino acids, which means that our bodies do not produce them and must get them from food. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Histidine is unique in that it’s only required during infancy.
Proteins do a lot of work throughout the body. They embed themselves in your cells to regulate what goes in and out. They even envelop and transport some molecules to other locations in the body. Enzymes that catalyze the various chemical reactions in your body are made of folded chains of amino acids. The body creates hormones like leptin, immune proteins like interferon, and antibodies using amino acids.
How Much Protein Do You Need?
Adults should get 10-35% of their calories from protein.
The USDA recommends that adults get 10-35% of their calories from protein. This range is set to cover 97-98% of the population, and your needs may vary based on age and health status. Protein, like carbohydrates, provides four calories of energy per gram.
Sources of Protein
Whole, nutrient-dense foods are the best sources of protein. Notice I did not say they are the most concentrated sources of protein. So-called "high-quality" sources are very concentrated sources of peptides that share similar amino acid ratios with humans. Essentially, the more a source of protein resembles human tissue in amino acid composition, the better its "quality."
Regularly eating meat, just like regularly consuming concentrated sources of sugar, leads to several serious, and completely preventable health issues.[4, 5, 6] If you think eating organic, free-range, grass-fed meat is significantly better than factory farmed meat, then wouldn’t it also follow that soda with 100% organic high-fructose corn syrup is equally healthy when compared to regular soda? That’s clearly not the case. It’s important to understand that some foods have few redeeming qualities, organic or not. Just because something is less bad for you than the standard option doesn’t mean that it’s good for you.
Some plant foods, like nuts, seeds, grains, and vegetables, are called incomplete proteins because they do not contain all nine essential amino acids together, as meats, eggs and dairy products do. However, you won’t develop a protein deficiency on a plant-based diet as long as you eat a balanced diet that combines plant foods with different amino acids.
What Is Fat?
At nine calories per gram, fat is the densest source of energy in the diet. In the body, fats make up cell membranes, steroids, cholesterol, and 60% of your brain. Fats support the absorption of fat-soluble vitamins, cushion your organs, and act as your largest form of energy storage.
Dietary fats include saturated and unsaturated fats. Saturated fats tend to come from animal sources, while most plant fats are unsaturated. There are also important essential fatty acids, namely omega-3 and omega-6. As with essential amino acids, the term essential means that the human body cannot produce it, and we must get these from our diet.
There’s also an unnatural type of fat known as trans fats. Trans fats are a product of food manufacturing and are created by hydrogenating (or adding hydrogens to) less stable unsaturated liquid fats to solidify them, and hence make them more shelf stable. This process prolongs the life of processed food products. Trans fats are often described as poison, and it’s a description that’s fairly accurate. Trans fats raise your "bad" LDL cholesterol and have no place in a healthy diet.
How Much Fat Do You Need?
Fats should account for 25-35% of your daily calories.
Like carbohydrates, the popularity of fat rises and falls with public opinion and even medical opinion as new diets and research emerge. Currently, according to the USDA, fats should account for 25-35% of your daily calories. Fats are undoubtedly a necessary component of a healthy diet. Some of the best sources of healthy fats are nuts, seeds, coconuts, avocados, and olives. Like the most healthy sources of proteins and carbohydrates, the fats in nuts and fatty fruits contain fiber, beneficial micronutrients, and phytonutrients that keep you healthy.
Sources of Fat
Just like with carbohydrates and protein, the best sources of fat are plant-based and nutrient dense. Nuts, seeds, avocados, olives, coconut, and dark chocolate are all excellent sources of fat that come with a healthy serving of phytonutrients and fiber. As always, I recommend whole foods over processed ones.
However, if you’re looking for healthy oils, you have many options: flaxseed, hemp seed, avocado, grapeseed, sunflower, walnut, sesame, and coconut oils. I highly recommend flaxseed oil for room temperature or colder dishes like salad dressings or hummus. For cooking, use oils that have a higher smoke point like grapeseed, coconut, avocado, and sesame oil. When purchasing oils, always make sure the label says "expeller-pressed" and "unrefined." Otherwise, the oil may have been extracted using chemicals and subjected to extensive processing, which disturbs the delicate essential fatty acids in the oil.
Don't Focus on Macronutrients Too Much
When you focus on optimizing the ratios or percentages of your macronutrients, you might forget to concentrate on the quality of the food itself. Make sure to eat a balanced combination of whole, plant-based foods that contribute to your health. Your macros may vary from one day to the next, but your body’s needs may differ based on your activity level, health status, schedule, or other factors. If you’re trying to make a big change in your diet and lifestyle, consider working with a certified dietitian or nutrition counselor that can evaluate your needs, help you set achievable goals, and create a personalized diet plan for you.
When you increase the proportion of one macronutrient, it necessarily involves a decrease in the proportion of the other macronutrients. For example, a high-fat diet is usually relatively low in carbohydrates or proteins, while a high protein diet is lower in carbohydrates and fat.
You can consume various proportions of the three major macronutrients (not including alcohol) and still have a healthy diet. However, there is a growing body of evidence that a significant imbalance in the proportions of macronutrients negatively affects micronutrient intake and may even increase the risk of disease. Diets that are extremely low in protein, for example, are linked to an unhealthy immune system, low birth weight, and slow development.[7, 8] Diets should have a lower limit of 10% protein for a properly functioning and healthy body.The USDA issued these major recommendations for a healthy diet.
- Follow a healthy eating pattern throughout your lifespan
- Focus on variety, nutrient density, and amount of food within your calorie limits
- Limit calories from added sugars and saturated fats and reduce sodium intake
- Shift to healthier food and beverage choices
The ultimate goal of any good diet is to fuel your day-to-day activities while keeping yourself nourished. Make sure the foods you chose are micronutrient dense. Nutrient density means that your food contains high quantities of nutrients. These micronutrients are required in significantly smaller amounts, but they have a large impact on your health. If you want to learn more about what these important nutrients are, check out my micronutrients article.
- "Dietary Guidelines for Americans 2015-2020. 8th Edition." U.S. Department of Agriculture. 9 May 2018. Accessed 9 May 2018
- CDC. "Adults Meeting Fruit and Vegetable Intake Recommendations — United States, 2013." Centers for Disease Control and Prevention. CDC, 10 July 2015. Web. 15 Feb. 2017.
- "Amino acids." Medline Plus. 7 Feb. 2017. Web. 15 Feb. 2017.
- Micha, R, et al. "Red and Processed Meat Consumption and Risk of Incident Coronary Heart Disease, Stroke, and Diabetes Mellitus. A Systematic Review and Meta-Analysis." Circulation. 2010;121(21),2271-83.
- Pan, An, et al. "Red Meat Consumption and Mortality: Results from Two Prospective Cohort Studies." Archives of Internal Medicine. 1994;172(7),555–563.
- Young VR, Pellett PL "Plant Proteins in Relation to Human Protein and Amino Acid Nutrition." Am J Clin Nutr. 1994;59(5),1203–1212.
- Chang, C.Y., D.S. Ke, and J.Y. Chen. "Essential Fatty Acids and Human Brain." Acta Neurologica Taiwanica. 2009;18(4),231–241.
- "Nutrient Reference Values." Ministry of Health, Australian Government. Updated 4 Feb. 2014. Accessed 8 May 2018.
†Results may vary. Information and statements made are for education purposes and are not intended to replace the advice of your doctor. If you have a severe medical condition or health concern, see your physician.