Macros Explained

If you’ve spent any time around nutrition, fitness or healthy living, you’ve probably heard the term “macros”.

But what exactly are macros? Why do they matter? And can your genetics influence the way your body responds to different macronutrients?

Understanding your macros can help you move beyond simply counting calories and start thinking about what you’re eating, how much you’re eating and how your individual body may respond to your diet.

What are macros?

“Macros” is short for macronutrients: the nutrients your body needs in relatively large amounts to provide energy and support essential functions.

There are three primary macronutrients:

1. Protein

Protein is made up of amino acids and plays a vital role in maintaining and repairing the body.

It is particularly important for:

• Muscle growth and repair

• Maintaining lean muscle mass

• Supporting enzymes and hormones

• Immune function

• Helping you feel satisfied after meals

Protein is found in foods such as meat, fish, eggs, dairy products, tofu, beans, lentils and other plant-based sources.

2. Carbohydrates

Carbohydrates are one of the body's main sources of energy.

When you eat carbohydrates, your body breaks them down into glucose, which can be used for energy or stored for later use.

Carbohydrates are particularly important for:

• Providing energy for everyday activity

• Supporting exercise and physical performance

• Fueling the brain

• Replenishing glycogen stores in muscles and the liver

Carbohydrate-rich foods include fruit, vegetables, grains, rice, pasta, potatoes, oats, bread and legumes.

3. Fat

Dietary fat is essential for health and isn't something that should simply be avoided.

Fat helps with:

• Hormone production and signalling

• Absorption of fat-soluble vitamins A, D, E and K

• Cell structure and function

• Providing a concentrated source of energy

• Supporting brain and nervous-system function

Sources of dietary fat include olive oil, nuts, seeds, avocado, oily fish, eggs and dairy products.

What does each macro do in the body?

While protein, carbohydrates and fats all provide energy, they perform very different roles.

Protein and carbohydrates provide approximately 4 calories per gram, while fat provides approximately 9 calories per gram.

But nutrition isn't simply a mathematical equation.

Two people can consume the same number of calories while eating very different proportions of protein, carbohydrates and fats - and the nutritional quality, satiety, performance and overall experience of those diets can be very different.

This is why looking at macronutrient balance alongside overall food quality, micronutrients, fibre, hydration and lifestyle factors can be much more useful than focusing on calories alone.

Why are macros important?

Your macronutrient intake can influence a number of aspects of your nutrition and lifestyle.

Energy

Carbohydrates and fats are important sources of energy, while protein can also be used for energy when required.

Getting the balance right can help support your daily activity and exercise.

Muscle and recovery

Adequate protein provides the amino acids needed for muscle maintenance and repair.

For people who exercise regularly, getting enough protein alongside appropriate overall energy and carbohydrate intake can be particularly important for recovery and performance.

Satiety and appetite

Protein, fibre-rich carbohydrates and dietary fats can all contribute to feelings of fullness.

The right combination can make meals more satisfying and potentially make a nutrition plan easier to maintain.

Blood glucose and metabolic health

The type, quantity and combination of carbohydrates you eat can influence blood glucose levels.

However, your response isn't determined by carbohydrates alone. The overall meal, fibre content, physical activity, sleep and individual biology can all play a role.

Hormones and essential functions

Dietary fat and protein provide building blocks and nutrients involved in numerous biological processes, while carbohydrates can support energy availability and exercise performance.

The goal isn't to eliminate a particular macronutrient. It's about finding an appropriate balance for your individual needs and goals.

How are macros calculated?

Calculating someone's macros isn't simply a case of choosing a percentage of protein, carbohydrates and fat.

An estimated daily energy requirement may first be established. Macronutrient targets can then be set according to the individual's circumstances and goals.

Importantly, these calculations are estimates rather than exact measurements of what your body requires. Your needs can change over time as your body weight, activity, training, goals and lifestyle change.

Don't calculate your macros yourself

Online calculators can be useful for general education, but a generic calculation doesn't necessarily account for the full picture.

We don't recommend calculating your macros yourself without appropriate guidance.

If you'd like to understand what your personalised macronutrient targets could look like, speak to our team about our personalised macro calculator and guidance.

We can help you understand the numbers in the context of your individual goals rather than simply giving you a set of figures to follow.

What about genetics and macro metabolism?

This is where nutrition becomes particularly interesting.

We are all genetically unique, and our genes can influence aspects of how our bodies process nutrients.

Genetic variations can affect biological pathways involved in areas such as:

• Fat metabolism

• Carbohydrate metabolism

• Lactose and other nutrient digestion

• Appetite and satiety

• Lipid metabolism

• Glucose regulation

• Nutrient utilisation

This is one reason why two people can follow broadly similar diets and experience different responses.

However, it's important to understand that genetics are one piece of the puzzle.

Your genes don't operate in isolation. Your diet, physical activity, sleep, stress, environment, gut health, medications, age and many other factors can also influence metabolism and health.

Why consider genetic testing for nutrition?

A genetic test can provide information about specific genetic variants that may be relevant to nutrition and metabolism.

Rather than asking, “What diet works for everyone?”, genetic information can contribute to a more personalised question:

“What can we learn about how my individual biology may interact with different aspects of nutrition?”

This can be useful when building a personalised approach to nutrition.

For example, genetic information may provide insights into certain pathways involved in how an individual processes dietary fats or carbohydrates, or how they may respond to particular nutrients.

But genetic testing should not be viewed as a magic formula that determines exactly what you should eat.

The science of nutrigenetics — the study of how genetic variation can influence responses to nutrients — is an evolving field. Genetic results need to be interpreted carefully and alongside your wider health, lifestyle and dietary information.

Personalised nutrition starts with understanding you

There is no single macronutrient split that is perfect for every person.

Your nutritional needs can vary depending on your body, your lifestyle, your activity levels, your goals and potentially your individual genetic makeup.

That's why we believe nutrition should be approached as personalised rather than one-size-fits-all.

Understanding your macros can give you a practical framework for building your diet. Combining that information with professional guidance - and, where appropriate, genetic insights - can help create a more individualised approach.

Interested in finding out what your personalised macros could look like?

Don't calculate them yourself based on a generic online calculator.

Speak to our team to find out more about our personalised macro calculator and guidance, and how genetic testing may complement your individual nutrition journey.

Please note: Genetic testing is not a substitute for medical diagnosis or treatment. Genetic results should be interpreted in context and do not, on their own, determine an individual's ideal diet or predict future health outcomes.