What are Macros?

January 4, 2021

When people are talking about nutrition and weight loss, you may hear them mention macronutrients (or macros for short).

So, what exactly are macronutrients? These are nutrients we need to fuel and give our body energy.

Where might we typically find these? Our 3 main sources are in fats, proteins and carbohydrates.

Importance of Macros

When the goal is a change in weight, one of the biggest components of change is nutrition and more specifically calorie intake. It is the number of macros within those calories that are responsible for weight loss or gain.

As cliché as it sounds, everyone is different, and the perfect balance that works for one may not work for another. Keeping a food diary is a handy tool when you begin to monitor and count your macros. It can help you get the right balance of nutrients needed for your weight goals, resulting in your desired body composition and athletic goals.

Your goals and lifestyle will determine your ideal macros count, For example:

1. To build muscle – focus on a good amount of protein.

2. To lose weight or get lean– reduce your sugar intake.

3. For endurance or those who exercise a lot – include a variety of carbohydrates in your diet.

Once you understand macros, how they are balanced, and the impact they can have on achieving your goals, you can begin to utilise this knowledge to make your targets more attainable.

So, let’s do just that, and get a better understanding of those 3 main macro sources.


Protein is the building blocks of muscle, and if you do not consume enough it will hamper your ability to develop them.

Although it is recommended that 10% of your calories should come from protein, if you are trying to retain or build muscle you will need a lot more. I would suggest 20 to even 50% of your calories from protein.

Proteins are also very filling, curbing those hunger cravings and helping you keep your weight under control.

The breakdown:

100g protein = 400 calories

So if,

100g chicken breast = 30g protein (+ 3g of fat)


120 calories (from protein)

30 calories (from fat)


Despite their stigma within the fitness community, carbohydrates are the bodies quickest and easiest energy source. There are 2 types of carbohydrates, simple and complex.

Simple carbohydrates (or simple sugars) are found in refined sugars like sweets and chocolates but can also be found in some nutritious foods like fruit and milk. Your body burns this type of carbohydrate quickly making it a great source of immediate fuel. However, when you overindulge in these sugars and surpass your ‘need’ for immediate fuel, your body will inevitably store this as fat.

Complex carbs (or starches) can be found in grains, such as pasta, bread and rice. This type of carbohydrate burns at a slower and steadier rate than its counterpart and helps you feel fuller for longer. Ideally, you want to mix and include both in your diet.

Let’s face it, carbs taste good! So, unless you are going hard with your training it is recommended that only 5% of your daily calorie intake comes from sugar. You a far more likely to get better results, especially aesthetically if you lower your carb intake and replace those calories with one of the other macronutrients.

The breakdown

100g carbohydrates = 400 calories

So if,

100g grains (e.g. pasta, bread and rice) = 30g carbs


100g grain = 120 calories


Quite literally the ‘F’ word in nutrition, fat is the slowest burning fuel resource our body can use. Although it is at our disposal, the body naturally taps into this in a ‘last case scenario’ making fat difficult to get rid of.

That being said, there are advantages to having certain fats in your diet such as essential fatty acids that our body cannot produce and for vitamin absorption.

Fats can be found in meat, fish, nuts and oils and are split into 3 main groups – saturated, unsaturated and trans-fats.

Saturated fats – solid at room temperature (red meat, poultry skin, coconut oil and butter)

Unsaturated fats – liquid at room temperature (vegetables, nuts, fish, avocado)

Trans-fats – are mostly artificial, made through an industrial process to last longer (cookies, doughnuts, French fries and other deep-fried foods)

The breakdown

100g fat (whichever type) = 900 calories

Therefore, they are the most calorie dense macronutrient.

Fun Fact: 100g nuts = 600 calories vs 100g pure sugar = 400 calories

Still nuts about nuts?

Calculating your macros

Its pretty simple, find out the weight of your macronutrient then work out it’s calorie content:

Protein and Carbs = 4 calories per gram

Fat = 9 calories per gram

But how do we factor in alcohol?

We should look at alcohol as a ‘fourth macro’. However, it is one to be avoided as much as possible. Speaking realistically, most people enjoy a little tipple from time to time. If you do, include alcohol into your carbohydrate allowance:

1g alcohol = 7 calories so,

1 unit alcohol = 70 calories and,

1 pint beer (3 units) = 210 calories.

The sustainability of it all

Counting your macros can seem daunting and time consuming. If you are finding it over whelming, try getting your calories right first. It is all a process and the best way to achieve your goal is one step at a time. Do not forget that a food diary can be hugely beneficial as well as a well thought out meal plan. Your personal trainer can help you with this, should you need it.