Nutrients are environmental substances used for energy, growth, and bodily functions by organisms. Depending on the nutrient, these substances are needed in small amounts or larger amounts. Those that are needed in large amounts are called macronutrients.
There are three macronutrients required by humans: carbohydrates, fats, and proteins.
Carbohydrates are sugars that break down inside the body to create glucose. Glucose is the primary source of energy for the brain, muscles, and other essential cells.
There are two main types of carbohydrates, simple and complex. The more refined the carbohydrate the more quickly it is converted to glucose and released into the bloodstream. Refined or simple carbohydrates should make up only about 10% of your daily carbohydrate intake.
Complex carbohydrates release glucose more slowly into the bloodstream providing more stable and sustainable energy levels to the body.
Dietary fats are essential to give your body energy and to support cell growth. They also help protect your organs and help keep your body warm. Fats help your body absorb some nutrients and produce important hormones, too.
Your body uses protein to build and repair tissues. You also use protein to make enzymes, hormones, and other body chemicals. Protein is an important building block of bones, muscles, cartilage, skin, and blood.