7 Essential Nutrients – How Your Body Uses Them


Every living thing needs sustenance to survive. Single-celled amoebas eat algae, bacteria, plant cells, and anything else they can get their pseudopods on. Us human beings are more complex, and need to ingest a variety of things to keep our bodies and minds functioning correctly. To be more precise, we need at least 7 essential nutrients to stay healthy, and in this article, we’ll explore each of them in detail.


Protein is a macronutrient made up of around 20 different amino acids, which make up about 20% of our entire weight (if fat is ignored)1. Protein is a “building block” nutrient that allows our bodies to perform a number of functions:

Build new cells

When we consume protein, new cells are built using the amino acids found within. This includes your bones, muscles, cartilage, skin, hair, and nails, which all require protein to remain intact.

Repair damaged cells

In addition to building brand new cells, protein has the amino acids needed to repair damaged cells. As protein is broken down into amino acids through the digestive process, they’re ferried off to damaged cells to do their repair work2.

Oxygenate our bodies

Our red blood cells contain the protein haemoglobin, which transports oxygen around our bodies, drops it off where it’s needed, and also gives our blood its distinctive red colour.

Aids digestion

Our digestive system uses enzymes to break down food. About half of the protein that we eat goes into making enzymes, which means that in order to digest our protein, we need to eat protein—a circular dependency that is sure to boggle.

Regulates our hormones

The amino acids found in protein are used to produce certain hormones, such as insulin, estrogen, and hormones that help to control your appetite and hunger.

Getting enough protein every day is vitally important. The amount of protein that you need varies depending on your age, gender, weight, and overall health. If you’re concerned about not getting enough protein in your diet, it’s best to talk to a qualified nutritionist.


Carbohydrates provide a “ready-to-go” source of energy the body can use to power our cells. When we eat carbs, our body breaks them down into glucose, which gets rapidly absorbed into our blood, and enters our cells with the help of insulin. However, if we consume too many carbs, it can be converted into fat—our body’s longer term “reserves” of energy for when we’re starving. This may have been useful to our ancestors who couldn’t count on regular meals, but can lead to obesity in today’s food abundant world. The problems that occur when carbs are eaten too frequently in excess, can cause insulin resistance and mess up the hormones Grehlin and Cholecystokinin(CCK) leading to hunger cravings. With this in mind most people recommend matching carbohydrate intake to personal body types, lifestyle activities, and health outcomes.

Carbohydrates can be further divided into two key types:

Sugar (simple carbs)

Sugars are very simple carbohydrates that include fructose, glucose, and sucrose. These require little work from your body to break down into energy, but can be harmful for the production of different metabolites. If we’re feeling a little stressed and mindlessly consume an entire tub of Ben & Jerry’s, we get a massive hit of glucose that quickly finds its way to our cells, providing us with a burst of energy, but also an inevitable crash. Unfortunately this regular indulgence can damage our metabolism over time, and be a disadvantage for long term metabolic flexibility, stability, and health outcomes13.

Starch (complex carbs)

Starches are more complex carbohydrates and contain long chains of glucose molecules, which your body takes more time to process, and provides you with energy much more slowly. Starch is found in plant foods—examples include brown bread, pasta, rice, potatoes, squash, and a ton more.

In addition to giving us a slightly slower and more steady release of energy, complex carbohydrates can also provide us with fibre (great for digestion)3.

There is also a type of starch called resistant starch. This is a fantastic fuel for your body’s microflora and has been shown to actually help with blood glucose balance, improved sleep, enhanced energy, improved digestion, and bowel movements14.


Fibre is a type of carbohydrate that we cannot digest. It comes from plants, specifically the plant’s cell walls, which is why eating the skins of fruits and vegetables are a good source of fibre. Some don’t consider fibre to be one of the 7 essential nutrients, because we don’t need it to survive. Despite this, it can still be considered an important nutrient for overall digestive function12.

Fibre can be further categorised into two types:

Soluble fibre

Soluble fibre dissolves in water, which creates a gel-like substance that improves digestion by feeding microflora, and can assist natural detoxification processes. Foods that include this are grains like oats, fruits like apples and pears, and vegetables like broccoli and brussel sprouts, to name a few.

Insoluble fibre

Insoluble fibre cannot be digested and often stays fibrous, but it attracts water into your stool, making it softer and easier to pass. This type of fibre leads to a healthier bowel, and may even reduce your risk for diabetes4.


As with carbs, fats can provide you with energy, and they are not the demon they are sometimes made out to be. Fats help us to absorb certain important vitamins, and build cell membranes, as well as allowing our muscles to move, and our blood to clot so that we don’t bleed to death. It also allows our body to defend itself through inflammation, when it needs to.

Fats are made up of carbon atoms bonded to hydrogen atoms, and the different types of fats depend on the length and shape of their carbon chain, which often translates into how easy they are to produce, metabolise, or digest5.

These are the four key types of fats.

Saturated fats

Saturated fats are a hot topic at the moment, and for good reason. They’ve been demonised for 40 years, but latest research has shown how beneficial they are to long term health goals, improvements to energy levels, bone health, lung health and even reducing cholesterol levels.

The problems sometimes come in the form and source of the fat consumed—these are the main types.

Trans fats

Trans fats have zero health benefits, and are considered so detrimental to our heart health that they’ve been banned by a number of countries. Unfortunately, Australia isn’t one of them, and there’s no legal obligation to include trans fat information on nutrition labels.

Trans fats often come from the industrial processing of vegetable oils. Foods to watch out for include fried fast food (fried chicken, battered fish, fries, etc.), baked goods such as cakes, pastries, and doughnuts, as well as pizzas, certain potato chips, meat pies, sausage rolls, and more, from low quality sources7.

Monounsaturated fats

Monounsaturated fats are one of the healthiest fats, found in foods such as avocados, olive oil, and macadamia nuts. They’re commonly found in the “Mediterranean diet,” which is regarded as one of the healthiest ways to eat.5 This type of fat is more stable in cooking than polyunsaturated fats, is non inflammatory, and often provides additional nutrients for cell growth and repair, such as polyphenols and vitamin E.

Polyunsaturated fats

Polyunsaturated fats can come in the form of Omega-6 fatty acids (from sources such as soy oil, sunflower oil, etc.) which can be relatively inflammatory compared to the more anti-inflammatory Omega-3 fatty acids (from sources such as fish and flax seed). It is therefore important that a balance between these two types of fat are obtained in the diet.

However it is very common for imbalances to occur from highly processed or poor quality diets that are much higher in Omega 6 fats than Omega 3 fats. Additionally, keep in mind that polyunsaturated fats are more prone to oxidation than the other types of fats, and should therefore be kept fresh and protected from light and heat to prevent them from causing oxidative stress in the body.


Minerals are micronutrients that support many of the body’s functions, including your metabolism, staying well hydrated, building strong bones and teeth, helping your heart to pump normally, and more. They also help to reduce inflammation, and prevent certain cancers.

Minerals that we need include calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, chromium, copper, fluoride, molybdenum, manganese, and selenium.8 Mineral-rich foods are everywhere, and include seafood, leafy vegetables, citrus fruits, whole wheat foods, eggs, milk, yogurt, cheese, nuts, legumes, potatoes, and more9.


As with minerals, vitamins are micronutrients that help to support our body’s functions and ward off disease, which is why the two are often lumped together. We need vitamins for good eye health, skin health, and bone health, and they may also lower the risk of lung and prostate cancer, as well as boost our immune system11.

There are 13 essential vitamins, which are A, C, D, E, K, and the B vitamins thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9) and cobalamin (B12)10.


Last but not least—water is our seventh essential nutrient. It makes up at least 60% of our bodies, and is critical for regulating our body temperature, our digestion, removing toxins, reducing inflammation, maintaining a healthy weight, protecting our tissues, helping us to absorb nutrients, and a whole lot more. Drinking more water is one of the best and simplest things you can do for your health!


  1. Marshall Brain, Proteins – How Cells Work | HowStuffWorks, HowStuffWorks
  2. Carolun L.Todd, 2019, Here’s What Actually Happens in Your Body When You Eat Protein | SELF, Self
  3. Starchy foods and carbohydrates – NHS, NHS
  4. Taylor Norris, 2018, Soluble vs. Insoluble Fiber: What’s the Difference?, Healthline
  5. 2019, The truth about fats: the good, the bad, and the in-between, Harvard Health Publishing
  6. Saturated Fat, Heart.org
  7. Daisy Coyle, 2018, 7 Foods That Still Contain Trans Fats, Healthline
  8. Definitions of Health Terms: Minerals, MedlinePlus
  9. 2020, Essential Nutrients: Vitamins & Minerals, Hemophilia Federation of America
  10. 2020, How much do you know about the 13 essential vitamins your body needs?, Reader’s Digest Canada
  11. Mandy Ferreira, 2020, 6 Essential Nutrients: What They Are and Why You Need Them, Healthline
  12. Jill Balla Kohn, 2016, Is Dietary Fiber Considered an Essential Nutrient?, Journal of the Academy of Nutrition and Dietetics
  13. Sarah A. Hannou, Danielle E. Haslam, Nicola M. McKeown, Mark A. Herman, Fructose metabolism and metabolic disease, The Journal of Clinical Investigation
  14. 2019, Why Resistant Starch ???, Focus Nutritional Medicine