Macronutrients are essential nutrients which provide all the necessary building blocks of life. They include protein, carbohydrates, fats and vitamins A, D, E and K2 (vitamin k1). These four macronutrients play crucial role in human physiology. They are required for growth and development; they regulate metabolism; they affect immune system function; and they have many other functions such as regulating blood sugar levels, controlling body temperature and maintaining bone density.
The composition of these four macronutrients varies among individuals. Individuals vary in their ability to absorb certain types of fat, proteins and carbohydrates. For example, some people cannot digest dietary fiber or are unable to break down plant starchy foods into simple sugars. Other factors may include genetic makeup, age and gender.
Therefore it is very difficult to give specific recommendations for each individual based on their unique nutritional needs.
However, there are some general guidelines that can be used to make informed decisions about your own nutrition. These recommendations will depend upon several factors including your age, gender, height and weight.
Protein: Protein is the most abundant macronutrient in our bodies. It is needed for muscle growth and repair and plays an important role in normal cell division. It is composed of smaller units called amino acids. There are 22 different types of amino acids.
Nine of these are called essential amino acids since they cannot be produced by the body and must be supplied in the diet. Sources of animal proteins contain all nine essential amino acids. However, plant sources of protein may be deficient in one or more amino acids. These plant sources do not contain all the essential amino acids and therefore should be eaten in combination to provide all the necessary amino acids. The table below shows the amount of protein contained in one serving of food.
Protein can be found in both plants and animals. It is commonly believed that meat is a better source of protein than plants. This is not necessarily true because some plant sources such as legumes, soy and whole grains contain all the essential amino acids in good amounts. Some vegetable sources of protein include peanuts, peanut butter, lentils, chick peas, navy beans, kidney beans and soybeans.
Fat: Fats provide more than twice as much calories as proteins or carbohydrates (nine calories per gram compared to four calories per gram). Dietary fat is also essential to good health. Fats help the body absorb vitamins A, D, E and K. They are also a source of energy since the body can burn fat instead of carbohydrates when there is limited access to food.
Fats also help the body maintain healthy skin and hair, create certain hormones, and support the immune system. Despite this, there has been a long-standing myth that fat is bad.
Sources & references used in this article:
Dietary supplements and health aids—A critical evaluation part 2—Macronutrients and fiber by MA Dubick – Journal of nutrition education, 1983 – Elsevier
Roundoc Rx: Aging Well: Part 2—Interventions That Affect the Aging Process by A Aragon, DR Moore – 2009
Part 2 of the Anabolic Burst Cycling System: The Bodybuilding Nutrition Breakthrough of the Century by R Rountree – Alternative and Complementary Therapies, 2010 – liebertpub.com