A nutrient is a chemical substance found in foods that is used in the human body. Essential nutrients cannot be synthesised by the body, therefore they have to be included in the diet. A nutrient is a substance that provides nourishment essential for growth and the maintenance of life.
There are six classes of nutrients:
The three types of nutrients that are commonly used as energy sources are carbohydrates, lipids (fats) and proteins. Carbohydrates are preferentially used as an energy source because they are easier to digest and transport. Lipids can store more energy per gram but are harder to digest and transport (hence are used for long-term storage). Protein metabolism produces nitrogenous waste products which must be removed from cells.
The relative energy content of carbohydrates, proteins and fats are:
Carbohydrates are critical to the function of your body. Carbohydrates are broken down into glucose, which is the primary source of energy for your body and brain. They also help stabilise blood sugar levels and preserve muscle mass by preventing the breakdown of proteins for energy.
Complex carbohydrates take longer to break down, which can help you feel fuller for longer and keep blood sugar levels regular. Whole grains, fruits and vegetables are a examples of healthy complex carbohydrates.
Proteins are made up of building blocks called amino acids, which are composed of even smaller units called peptides. There are 20 types of amino acids, all of which are important. However, nine of these are considered essential amino acids because they can’t be produced by your body.
The nine essential amino acids are:
While animal proteins provide adequate amounts of all essential amino acids, plant-based proteins are typically lacking in one or more.
Fat is an essential nutrient that provides energy, boosts the absorption of certain vitamins and helps protect your organs from damage. However, some types of fat are better than others.
Trans fats are a type of fat found in processed foods, baked goods and shortening. This type of fat significantly increases the risk of heart disease and should be avoided at all costs.
Unsaturated fats, on the other hand, can actually help protect the heart and aid in the prevention of heart disease. Healthy sources of fat include nuts, avocados, salmon, olive oil, flax seed and nut butters.
There are many different types of vitamins, each with its own specific function and role in the body, but all equally vital for maintaining optimal health. For example, Vitamin A is critical for the health of your eyes and skin, while vitamin K builds strong bones and is involved in blood clotting.
The essential vitamins that your body needs are:
There are 13 vitamins that our body needs, eight of which make up the B-group (or B-complex) vitamins. The best way to get in all of these vitamins is to eat a healthy and balanced diet with plenty of fruits and vegetables.
Vitamin D is necessary for the absorption of calcium and can promote good bone health, making it an especially important vitamin for women to help prevent osteoporosis. Vitamin D is produced in the skin as a result of sun exposure and can be obtained in small quantities through foods like mushrooms, eggs and fish.
Like vitamins, minerals are also important for helping your body function properly and stay healthy, and each comes with its own specific role. For example, Iron is key to blood production, while phosphorus strengthens the bones and teeth.
The minerals that your body needs include:
Calcium is the most important nutrient for bone health. Over 99 percent of the body’s calcium is found in the bones and teeth. Calcium is also involved in muscle contractions, nerve function and the movement of blood throughout the body. Calcium is found naturally in dairy products, leafy greens, white beans, and certain types of fish like sardines and salmon.
Sodium regulates fluid balance and blood volume while also keeping your nerves and muscles working correctly. Sodium should be included in moderation as excessive amounts can lead to high blood pressure in some people.
Potassium is an essential electrolyte that helps maintain fluid balance and blood pressure. It also is necessary for muscle contractions, heart health and regulating the pH level of your blood to prevent it from becoming too acidic. Bananas, spinach, tomatoes, potatoes, avocados, salmon and sweet potatoes are sources of potassium.
Water accounts for a pretty big portion of the body, making up somewhere between 55 percent to 75 percent of your body mass. The human body can survive for long periods of time without food. While you may be able to go without food for quite a while, even just a few days without water can be detrimental.
Water plays an essential role in waste removal, digestion and temperature regulation and makes up a core component of every cell in your body. Dehydration can lead to symptoms like dry skin, dizziness, fatigue, or a rapid heartbeat.
In addition to the things that you drink, you also take in water through the foods that you eat as well. Fruits and vegetables tend to have a higher water content and can help keep you hydrated.