macronutrients

Why do you eat food? 

You eat food to acquire its nutritive components. Different foods have different nutrients. The nutrients that your body uses in large amounts are called macronutrients. Your body uses these nutritive components for energy, and to maintain body systems and structure. It is important to note that a good diet is made up of foods containing different macronutrients. You are about to learn different sources of these macronutrients and how much your body needs. Let's go!

LEARNING OBJECTIVES

By the end of this lesson, you should be able to:

• Identify different macronutrients
• Describe sources of different macronutrients

Macronutrients are the nutrients we need in larger quantities that provide us with energy: in other words, fats, proteins, carbohydrates. Macronutrients are the cornerstones of our diet.

Along with energy, all of these macronutrients have specific roles in your body that allow you to function properly.

CARBOHYDRATES

All carbohydrates are eventually broken down into glucose, which is the main energy source for your body. In fact, specific organs, such as your brain, need glucose in order to function properly. You can make glucose out of necessity from proteins using gluconeogenesis. Beyond being the main energy source, there are carbohydrates that help synthesize specific amino acids and allow for consistent bowel movements. Fiber is a type of carbohydrate that cannot be broken down by your gastrointestinal tract. Therefore, this nutrient does not give you energy, but it does help rid your body of waste and keeps your intestinal tract healthy.

Some carbohydrates are considered simple and others complex.

• Simple carbohydrates are easy for your body to break down for energy or glucose. They have 1-2 sugar molecules and are found in sweet items like table sugar, honey, milk, and fruit. Fruit contains a natural sugar called fructose. It also contains vitamins, minerals and phytonutrients which promote healthy aging. 
• Chemicals and fiber. Fiber is not digested and hence increases the time needed to break down food items.
• Complex carbohydrates take more time to break down. They are long strands of sugar molecules strung together and typically have a savory taste. They are found in foods like starches and grains. They normally contain fiber unless they have been processed, where the grain has been stripped of its bran, which gives us white bread, white pasta, and white rice. These types of carbohydrates become easier for you to digest.

PROTEINS

Proteins allow your body to grow, build and repair tissues and protect lean body mass. They are composed of amino acids. Amino acids are building blocks of proteins, and they can be non-essential and essential. Essential amino acids are required through the diet while the non-essential amino acids are made by the body. They make up parts of bodily structures like connective tissues, skin, hair, and muscle fibers. Unlike carbohydrates, proteins don’t serve as a direct source of energy but work as building blocks for other structures in the body. The nutritional value of a protein is measured by the number of essential amino acids that it contains, which varies depending on the food source. Animal products contain all of the essential amino acids. Plant protein usually lacks at least one amino acid, so eating a combination of different plant proteins throughout the day is important for vegetarians and vegans.

FATS     

The distinction between saturated and unsaturated fats is important because your body only needs the latter. Unsaturated fats regulate metabolism, maintain the elasticity of cell membranes, improve blood flow, and promote cell growth and regeneration. Fats are also important in delivering fat-soluble vitamins A, D, E, and K into the body.

Your body does produce its own cholesterol, but a small amount introduced through your diet can help build cell membranes, produce hormones like estrogen and testosterone, help your metabolism work, produce vitamin D, and produce bile acids which help digest fat and absorb nutrients. However, a diet rich in cholesterol can increase the risk of heart diseases.

There are three types of fat; trans fat, saturated fat, and unsaturated fat.

• Trans fat should be cut out of the diet. 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.
• Saturated fat does not have any bends, caused by double bonds, In the molecule because it is saturated in hydrogen molecules. In large amounts, saturated fat is known to increase cholesterol levels and can increase the risk for heart disease. Decrease the amount of saturated fat in your diet to stay healthy.
• Unsaturated fat has at least one double bond causing bends in molecules. These are harder to stack and, therefore, are usually found in a liquid state at room temperature. Monounsaturated fats have one double bond while polyunsaturated fats have multiple or many. Unsaturated fats are known as healthy fats as they can decrease the risk for heart disease. These healthy fats originate from plant sources such as avocados.

Each macronutrient plays an important role in the body. Your body requires each of these macronutrients to perform optimally. Your body also needs micronutrients to remain healthy. They include vitamins and minerals. Micronutrients are required by the body in smaller amounts.