Understanding nutrients

Esteé van Lingen expands on what nutrients are and the difference between macronutrients and micronutrients.

Nutrition is a fundamental aspect of your life, influencing your health, energy levels and overall well-being. The food that you eat provides your body with essential nutrients (substances that provides nourishment essential for the maintenance of life and for growth) that are crucial for various functions in the body. Nutrients can be categorised into two main groups: macro- and micronutrients.

Macronutrients: energy providers and building blocks

Macronutrients are nutrients that your body requires in large quantities to provide you with energy, support growth and development and maintain overall health. There are three primary macronutrients: carbohydrates, proteins and fats.

  • Carbohydrates

These are the body’s primary source of energy. This can be found in various starches. Examples include grains (bread, pasta, pap, barley, quinoa, cereals etc), fruits, vegetables (especially starchy vegetables: corn, pumpkin, potatoes, sweet potato), legumes (beans, lentils, chickpeas) and dairy products.

When consumed, carbohydrates are broken down into glucose, which is used as a source of fuel for your cells.

Carbohydrates also play a crucial role in brain function and support physical activity.

  • Proteins

Proteins are essential for building and repairing tissue, as well as producing enzymes, hormones and other vital molecules. Protein is found in meat, chicken, poultry, fish, eggs, dairy products, legumes, nuts and seeds as well as plant sources like soya and tofu.

Amino acids, the small building blocks that make up protein, are used by the body to synthesise new proteins and perform various other functions.

  • Fats

Often also referred to as lipids, are essential for energy storage, insulating your organs and maintaining the health of cell membranes as all cell membranes consist of fat and the type of fat you consume, will determine how well the cell will let through nutrients into the cell and let waste out of the cells. Fat is also important when it comes to absorbing fat-soluble vitamins (A,D,E,K).

Healthy fats are found mostly in plant-based foods, such as avocadoes, nuts, seeds, olives, olive oil as well as in fatty fish, such as salmon, mackerel, pilchards, sardines and trout.

While unhealthy fats are mostly found in animal-based foods, such as processed foods (foods not in its natural form). For example, crumbed, battered, sausages, nuggets, Schnitzel, etc.) as well as fat on the meat, chicken skin and also fried foods. For example: takeaways (chips, fish, samosas, etc).

Macronutrients provide the body with kilojoules (calories) which are the measurements of energy. Carbohydrates and protein provide about 17 kilojoules (kJ) per gram while fats offer more energy at 38 kJ per gram.

The balance of these macronutrients in your diet can greatly influence overall health and body composition. For example, a diet high in carbohydrates can provide quick energy, but in excess can lead to weight gain especially when it’s not combined with an active lifestyle or exercise. A diet high in fat (especially unhealthy fats) can contribute to heart disease.

Micronutrients: the essential nutrient helpers

Micronutrients are the essential vitamins and minerals that your body requires in smaller quantities compared to macronutrients. However, these tiny powerhouses are critical for numerous bodily functions and overall health. Some common micronutrients include vitamins (A, Bs, C, D, E and K) and minerals (calcium, iron, magnesium and zinc).

  • Vitamins

These organic compounds play a variety of roles in the body. For example, vitamin C is known for its immune-boosting properties, while vitamin D is essential for bone health as well as plays a role in immunity. Different vitamins are found in various food sources, such as fruit, vegetables, dairy products and meats.

A deficiency in vitamins can lead to various health issues, including scurvy (lack of vitamin C), rickets (lack of vitamin D) and beriberi (lack of vitamin B1).

  • Minerals

Minerals like calcium, iron and potassium are inorganic nutrients that are essential for maintaining proper bodily functions. Calcium is crucial for strong bones and teeth. Iron is needed for oxygen transportation in the blood and potassium helps regulate blood pressure. Minerals are found in a variety of foods, with sources ranging from dairy products and leafy greens to lean meats and legumes.

Micronutrients are often involved in metabolic processes, acting as little helpers in the forms of coenzymes and cofactors that enable enzymes to function correctly. They also support growth, immune function and the maintenance of healthy skin, eyes and bones. An inadequate intake of micronutrients can lead to various health issues, including anaemia (iron deficiency), osteoporosis (calcium deficiency), and scurvy (vitamin C deficiency).

What is the difference between these two nutrients?


The primary distinction between macronutrients and micronutrients is the quantity required by the body.

Macronutrients are needed in larger amounts, typically measured in grams or kJ/calories whereas micronutrients are required in much smaller quantities, often measured in milligrams or micrograms.

Energy content

Macronutrients provide the body with energy in the form of kJ, while micronutrients don’t contribute to caloric intake. The energy content of macronutrients is significant in terms of maintaining energy balance and body weight.


Macronutrients are categorised into three main types: carbohydrates, protein and fats; each serving specific functions in the body. In contrast, micronutrients encompass a wide range of vitamins and minerals, each with its unique roles.

Food sources

Macronutrients are commonly found in foods such as grains, meat, vegetables and dairy products. In contrast, micronutrients are distributed throughout the food supply, with specific vitamins and minerals often associated with specific food groups. For example: vitamin C is found in citrus fruits, calcium is abundant in dairy products.

Roles in the body

Macronutrients primarily provide energy and structural components such as amino acids for protein synthesis. Micronutrients are involved in various metabolic and regulatory processes, acting as helpers or playing essential roles in specific bodily functions.


Macronutrients are typically measured in grams with recommended daily allowances (RDAs) or dietary reference intakes (DRIs) established to help meet your macro needs.

Micronutrients are measured in smaller units, such as milligrams or micrograms, and have their own recommended daily allowances.

How do you balance macro- and micronutrients in your diet?

A well-rounded diet should include an appropriate balance of macro- and micronutrients to support overall health and well-being. Here are tips for achieving this balance:

  1. Eat a variety of foods. Consuming a diverse range of food groups and colours ensures you receive a broad spectrum of macros and micros. Different foods offer various vitamins, minerals and macronutrient ratios.
  2. Ensure that you get the correct balance of carbohydrates, protein and fats to suit your needs and your lifestyle.
  3. Pay attention to portion sizes. Be mindful of portion sizes to avoid overconsumption of macronutrients, especially if you are trying to manage your weight. Use nutritional labels and food scales to ensure you consume the correct portions as well as learn to read and understand labels.
  4. Consider your needs. Your age, gender, activity levels, health status and stress levels can influence your macro- and micronutrients requirements. Consult a registered dietitian to tailor your diet to your specific needs.
  5. Plan balanced meals. When prepping meals, strive to include a source of each macronutrient along with variety of foods rich in micronutrients, such as fruits, vegetables and whole grains. These can also be distributed in different amounts throughout the day. For example: fruits as snacks or consuming grains instead of processed carbohydrates.
  6. Supplement if necessary. In certain situations, such as vitamin or mineral deficiencies, your healthcare provider may recommend supplements to ensure you meet your micronutrient needs. It’s called supplements for a reason; it should supplement a balanced diet and not take over the work of unhealthy diet and lifestyle.
Estée van Lingen is a registered dietitian practicing in Randburg and Fourways, Gauteng. She has been in private practice since 2014 and is registered with the HPCSA as well as ADSA and served on the ADSA Gauteng South Committee for 2020 – 2022.


Estée van Lingen is a registered dietitian practicing in Randburg and Fourways, Gauteng. She has been in private practice since 2014 and is registered with the HPCSA as well as ADSA and served on the ADSA Gauteng South Committee for 2020 – 2022.

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