What are Macronutrients?
Most of us have heard the term macro at some point or another. It is written about a lot, particularly when the subject is about eating healthy or losing weight. You may have heard it mentioned in terms of calculating or tracking macros, but what are macros?
Macros are macronutrients. The word macro means large, because your body needs these nutrients in large amounts in order to function at its best. In addition, all these nutrients provide your body with energy measured in the form of calories.
There are three types of macronutrients: carbohydrates, proteins, and fats.
Carbohydrates contain 4 kcal per gram
Proteins contain 4 kcal per gram
Fats contain 9 kcal per gram (this is roughly double the amount found in the other two macros)
Alcohol contains 7 kcal per gram (this macro is secondary, and many people don’t track it)
Aside from providing energy to perform bodily functions, each macronutrient has specific roles in your body’s ability to function at its best.
All carbohydrates are eventually broken down into glucose which is the main energy source for your body. In fact, certain organs, such as your brain, need glucose to operate at its most basic level. Your body can make glucose out of necessity from proteins through a complex process called gluconeogenesis. All carbohydrates are not created equal. Some are considered simple carbohydrates and others are complex.
Simple carbohydrates are easy for your body to breakdown for energy or glucose. They have 1-2 sugar molecules and are found in items that are usually sweet such as honey, table sugar, syrup, agave nectar, molasses, milk/yogurt, and fruit. Fruit contains a natural sugar called fructose. However, fruit also has vitamins and minerals (these are your micronutrients: nutrients needed in small amounts), phytochemicals (not a necessary nutrient, but can have many positive effects on health), and fiber. Fiber is not digested and therefore, increases the amount of time needed to break down the food item.
Complex carbohydrates take more time for your body to breakdown. They are long strands of sugar molecules strung together and typically have a savory taste. They are found in foods such as starches and grains: rice, pasta, bread, and starchy vegetables (potatoes, peas, corn). Other plant-based foods such as non-starchy vegetables (beans, nuts, and seeds) contain carbohydrates, but in lower amounts. Complex carbs normally contain fiber unless they have been processed, where the grain has been stripped of its bran (outer coating), which gives us white bread, white pasta, white rice, etc. These types of carbs become easier for your body to digest. Even though they are not sweet they will release glucose quickly just like a sweet simple carbohydrate.
Protein allows your body to grow, build and repair tissues, and protect lean body mass (your muscle mass). Protein is composed of amino acids. Amino acids are the building blocks of protein. There are 2 types of amino acids: non-essential and essential. Non-essential amino acids are not required to be consumed through the diet as your body can actually make these. Essential amino acids are required through your diet. Essential amino acids can either be used on their own or in some cases they are transformed into a non-essential amino acid. Protein rich foods include meat, poultry, fish, egg, milk, cheese, or other types of animal by-product foods. These protein sources contain all of your essential amino acids. This does not mean you have to eat animal foods to be healthy. You can get the proper amino acids from eating a variety of plant protein sources such as beans, lentils, nuts, seeds, and soy as well as lower amounts in grains, vegetables, and fruits.
Fat allows you to store energy, cushion organs, make certain hormones, absorb fat soluble vitamins, and helps with cell membrane integrity. There are three types of fat: trans fat, saturated fat, and unsaturated fat.
Trans fat - Most trans-fat comes from hydrogenating or adding hydrogen molecules to unsaturated fats. This produces a hydrogenated oil. These can be found in margarine, shortening, baked goods, doughs, and fried foods. If you see trans-fat on the label it should be avoided.
Saturated fat - does not have any bends, caused by double bonds, in the molecule because it is saturated in hydrogen molecules. Saturated fat is found mostly in animal sources with high fat contents such as fatty beef, lamb, pork, poultry with skin, lard, cream, butter, full fat cheese, and dairy.
Unsaturated fat has at least one double bond causing bends in the molecule. These are harder to stack and, therefore, are usually found in a liquid state at room temperature. The number of double bonds allows for the naming of unsaturated fats. Monounsaturated fats have one double bond while Poly unsaturated fats have multiple or many. Unsaturated fats are known as the healthy fat as they can decrease your risk for heart disease. These healthy fats originate from plant sources such as avocados, nuts and nut butters, seeds, olives, and oils (olive, canola, safflower etc.). They can also be found in animal sources such as fatty fish including salmon, mackerel, sardines, tuna, and herring.
The recommended amounts of these different macronutrients are usually referred to as macronutrient split. A good place to start is using the USDA recommendations:
Although these are healthy percentages, different combinations can help you achieve different goals or help manage different conditions. Everyone may thrive at different macro splits, so what works for one person may not work for everyone. For example, a higher protein percentage, may be more appropriate for someone trying to build muscle or lose body fat while maintaining muscle.
Downloading a tracking app can be helpful in finding and following where you are. MyFitnessPal is a great, free application that can be accessed on desktop and mobile where you can track daily intake.
Your goals should determine your macronutrient ‘split’. Talk to a nutritionist to determine what that split should be for you.
I hope this helps break down some of the basics of macronutrients.