Carbohydrates are composed of carbons, hydrogen, and oxygen.

Carbohydrates provide energy and serve as building blocks for bigger macromolecules. They are also essential for the nervous system’s proper functioning, heart, and kidneys (Green & Shellal, 2020).

Carbohydrates come in two forms: simple carbohydrates, and complex carbohydrates.

Simple Carbohydrates: consists of simple sugars (i.e. sugars found in food), and glucose (i.e. sugar found in the blood).

Complex carbohydrates: "Complex carbohydrates are long chains of simple sugars that can be unbranched or branched. During digestion, the body breaks down digestible complex carbohydrates into simple sugars, mostly glucose. Glucose is then transported to all our cells, stored, used to make energy, or used to build macromolecules. Fibre is also a complex carbohydrate, but digestive enzymes cannot break it down in the human intestine. As a result, it passes through the digestive tract undigested unless the bacteria that inhabit the colon or large intestine break it down" (Green & Shellal, 2020).

Proteins are macromolecules made from chains of amino acids. Amino acids contain hydrogen, carbon, oxygen, and nitrogen.

These proteins provide structure to bones, muscle, and skin, and play a role in conducting chemical reactions taken place in the body. They provide 4 kilocalories of energy per gram.

Examples of protein in food sources: meat, dairy products, seafood, and various plant-based foods

Lipids are insoluble molecules made of carbon, hydrogen, and oxygen.

Lipids serve as a major component of cell membranes, surround and protect organs (in fat-storing tissues), provide insulation to aid in temperature regulation, and regulate many other body functions (Green & Shellal, 2020).

Example of lipids: butter, oil, meats, dairy products, nuts, seeds, and processed foods

Water is composed of hydrogen and oxygen. We require large intakes of water in our body to function.

Water is required for transportations in and out of the body, chemical reactions to take place, organs to be cushioned, and to keep a normal temperature.