We have all heard the phrase “you are what you eat” before. And as obvious as it is that you will not turn into a carrot if all you eat is carrots, there is some truth behind this phrase.

The food that we eat provides building blocks for our body to use in its makeup.

What we eat each time has an influence on which building blocks will be available (and which won’t) to reassemble into our own tissues and organs. The study of how food affects the body is known as nutrition, and proper nutrition can help us prevent diseases, manage chronic illnesses, promote a certain level of energy, and help in achieving and maintaining a certain weight. But before we can discuss the science behind health promotion and disease prevention in the context of nutrition, we must get a solid grasp of nutritional basics.

Nutrients are chemicals in food which are critical to human growth and function. Within the category of nutrients there exists a subcategory: macronutrients. Macronutrients are the only types of chemicals in food which provide the body with energy, just as gasoline would for a car or batteries would do a flash light. We need this energy to stay alive and to keep our body functioning. Most of us know this type of energy as “calories”, and that is precisely correct. Calories are just a unit of measurement to communicate how much energy is available in a certain food. The following are macronutrients which fuel our bodies and support normal function and health:

Carbohydrates

Carbohydrates are the body’s primary source of energy, specifically for the brain and during physical exercise. Thus it is essential that ample supply of carbohydrates is available for our brain to function appropriately. Carbohydrates are found in a large variety of foods: rice, wheat, other grains, vegetables, fruits, dairy products, legumes, and even seeds and nuts. Simple carbohydrates are known as sugars or simple sugars and they include glucose, fructose, galactose, lactose, maltose, and sucrose. These types of carbohydrates are commonly found in fruits, table sugar, honey, dairy, corn syrup, sweeteners, and beer. Meanwhile, complex carbohydrates include starch, glycogen, and most dietary fibres. They can be found in grains, legumes, potatoes and yams. Our body breaks down the long chain of sugars in complex carbohydrates when we need more readily available energy. Fibres help with nutrient absorption (allowing nutrients to enter the gates of a bloodstream) and with promoting digestion (helping food more through the digestive system).

Fats/ Lipids

Fats are what provide our bodies with energy during rest and low intensity exercises. Fats are also essential in allowing absorption of certain vitamins, specifically K, A, D, and E. They are found in oils, butters and as animal fat in many meats. Two of the most essential fatty acids are lonoleic acid (omega-6) and alpha-linolenic acid (omega 3). Fats have the roles of protecting our vital organs, regulating hormone production (including of reproductive hormones like estrogen and testosterone), helping regulate our body temperature, providing our brains with fuel and many more.

Proteins

Protein is the main macronutrient which helps support tissue growth, repair and maintenance. When we ingest proteins our body breaks it down into basic building blocks, called amino acids. These amino acids are then reassembled to build our own body proteins (in muscle, blood, bone, etc.). Imagine these amino acids as Lego pieces being taken apart and built together into new shapes and forms. Proteins can be found in meats, seafood, dairy products, nuts, seeds, legumes, and in some vegetables and grains.

The institute of medicine in Washington declared that the acceptable macronutrient distribution ranges for adults are 45%-65% for carbohydrates, 20%-35% for fats, and 10%-35% for proteins.

However, every person has their own unique nutritional needs (based on hormone levels, age, metabolic rate, and much more).

And the distribution of macronutrient intake should be planned with the goal of meeting one’s individual caloric needs and preventing any nutritional deficiencies or toxicities.