What are Macronutrients?

What are Macronutrients?

Do you remember the days when you could look at the wrapper of your favourite snack, see the calorie count and that’d be it: Choice made? Low daily calories = good? Ahhh, good times.

Well it's a little bit more complicated than that. Let's talk about macronutrients.

You’ve probably heard the term ‘macros’ batted around on blogs about keto diets or heard the question "does it fit your macros?" by every fitness blogger and their dog (or cat). Counting your macros can play a BIG role in helping you reach your ultimate #BODYGOAL, or even just look after our diet, body and health.

Whether you’re trying to get in shape or look after your weight, you’ve got to know about macros. The good thing is even if you don’t know exactly what the term means, you probably already understand some of the basics.

So what the heck are macros?

Macro is a shorthand term for macronutrients (ie. big-nutrients!) as opposed to micronutrients (small nutrients).

There are three types of macronutrients: carbohydrates, fat and protein. Each of these macronutrients plays a different role in the body. Carbs are an efficient fuel source, fat supports cell functionality, provides a (very!) slow release form of backup energy and can help you feel full. Protein is incredibly important for a number of reasons, mostly notably building lean muscle mass and repairing tissues.

All of our food is made up of different macros. Sometimes we like to think of pasta as pure carbs or chicken as protein, when in reality they consist of a variety of macro and micronutrients.

Finding balance is key, although what balance means to you depends on what you’re trying to achieve. Let’s first explain what the difference between the various nutrients is.

Carbohydrates ‘Carbs’

Carbs are your body’s go-to energy sources. Found in nearly all plant based foods, carbohydrates come in three forms. Simple carbs, complex carbs and fibre.

Simple carbohydrates (sugars)  are rapidly converted by our body into glucose, our muscles main energy source.  While they’re sweet and rather delicious, this rapid conversion of sugars into glucose has the knock on effect of increasing your blood-sugar levels excessively. If your blood-glucose levels get too high, the excess gets converted into fat.

Simple carbs do have a use though, they’re handy during or after exercise to boost your blood-sugar levels when you’re tired.

Complex carbs, like brown rice and whole grains and oats (which is why we love them!) are converted into glucose very gradually, maintaining your blood sugar levels and allowing your body to use your energy stores efficiently.

Fibre is also considered a carbohydrate, but it doesn’t really count as we can’t digest it (though it does play an important role in digestion). If you’re calculating your net carbs, discount fibre from your total carbohydrate macros.

If you exercise regularly you’ll have no problem chowing through most of the carbs you consume however if you don’t burn them off, they can convert into fat.

Each gram of carbohydrates contains 4 calories of energy, whether it’s simple or complex.

Food with carbohydrates: bread, pasta, legumes, vegetables, fruit.


We’ve been taught for years to avoid and fear fat, but in reality it plays a critical role in allowing our body to function correctly and we need to get the right amounts.

Containing 9 calories per gram, fat is incredibly calorie dense making it a very useful fuel source, especially for endurance athletes (and bears, if you’re the hibernating type).

Fat plays a host of more important roles such as providing our body with the resources it needs that help control growth, immune function, reproduction and various aspects of your metabolism. Fats are also where our body retains a number of important fat-soluble vitamins such as Vitamin A, D, E and K.

While most of us will be focussed on keeping fat levels down, it’s important to get enough fat, and try to stick to healthy unsaturated fats, such as those found in the oily fish, nuts and olive oil.

Lastly, fat is extremely good at helping you feel full, which makes a lot of sense when you think about it. Having a little bit of fat in every meal could go a long way to helping you eat fewer overall calories, if that’s your goal.

Foods high in fat: red meat, butter, full fat dairy.


Protein is a key component in nearly every cell in our body. From hair and nails to skin, blood and bones - protein is a big player.

More and more, the benefits of protein are becoming clear to health-conscious folks, not just hardcore dumbbell worshippers.

Protein is made up of 22 amino acids. 9 of these are called essential amino acids of which we’re unable to synthesise in the body, which is why we need to source them from our food.

In the absence of carbohydrates, protein can be used as an effective energy source, however it’s much more important for its role in preserving and building lean muscle. Without protein, we’re unable to effectively rebuild and repair muscle tissue. Not only that, but protein creates antibodies for our immune system and produces a whole host of hormones and enzymes in the body.

The main and arguably ‘best’ sources of protein come from meat and milk as these are ‘complete’ proteins that contain all 22 amino acids.

For that reason it used to be somewhat difficult for vegetarians and vegans to get the right amount of protein in their diet. These days it it’s getting ever easier to get the right amount of protein in the food you eat though, partly through supplements, but equally through a better understanding of the nutritional value of the food we eat.

Foods high in protein: meat, dairy, beans, fish...Oatein bars

Bonus Round: The Secret Macronutrient

Guess what, there’s a fourth micronutrient: alcohol. For obvious reasons it’s not really talked about in the same context as the three main macros. However it‘s important to stress how high in calories in general alcohol is, at 7 cals per gram.

Balancing Your Macros: Defining Your Goals

So after all that...why does it make sense to count macros instead of just counting calories?

As we’ve already established, the three macronutrients each play a different nutritional role in the body. Let’s say you’re looking to hit 2000 calories per day, it’s safe to say that if 70% of that 2000kcals is comprised of fat, you’re probably not going feel at your best.

Determine Your Calorie Needs

Before you can work out your macros, you need to know your overall calorie requirement.

To work this out you need know your basal metabolic rate (BMR). This is essentially how many calories your body uses at rest and then multiply that figure relative to how much exercise you do. It sounds more complicated that it is, but we won’t judge you if you use this handy calculator.

Work out your Basal Metabolic Rate:

  • Men: calories/day = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) + 5
  • Women: calories/day = 10 x weight (kg) + 6.25 x height (cm) – 5 x age (y) – 161

Next, multiply that figure by how much exercise you do.

  • Sedentary: x 1.2 (limited exercise)
  • Lightly active: x 1.375 (light exercise less than three days per week)
  • Moderately active: x 1.55 (moderate exercise most days of the week)
  • Very active: x 1.725 (hard exercise every day)
  • Extra active: x 1.9 (strenuous exercise two or more times per day)

Let’s say your estimated calorie intake per day to maintain your weight is 2000 calories. With that established, what do you want to achieve? There are three goals most of us will be looking for when understanding our diet

  • Weight loss
  • Gaining muscle
  • Maintaining good body makeup (maintaining weight)

If you’re looking to lose weight, you’ll need to reduce your overall calorie intake, a reduction of around 10% or 200 calories per day is reasonable. For gaining muscle, you’ll sometimes need to increase your overall calorie intake. More often than not however, the specific makeup of your food, or macros play a more important role.

Establishing Your Ideal Macro Ratio

For most people, a healthy ratio of macros looks something like this:

  • 45-65% calories from carbs
  • 10-35% from protein
  • 20-35% from fat

These recommendations are designed to fit a wide range of people of different activity levels, but they’re a good starting point for everyone.

A good macro ratio for weight loss would look something like this:

  • 50% Carbs - (50% of 2000 cals = 1000 cals of carbs)
  • 25% Protein - (25% of 2000 cals = 500 cals of protein)
  • 25% Fat - (25% of 2000 cals = 500 cals of fat)

To break that down further, remember that 1g of carbs and protein equals 4 calories and 1g of fat is 7 cals.

  • 50% carbs - 1000 cals/4 = 250g of Carbs
  • 25% Protein - 500 cals/4 = 125g of Protein
  • 25% fat - 500 cals/7 = 71.4g of Fat

You can fine tune them further to suit your needs. For athletes looking to build a lot  of muscle mass while cutting fat, a greater amount of protein would be recommended, for instance:

  • 40% Carbs -   (40% of 2000 cals = 800 cals of carbs)
  • 30% Protein -  (30% of 2000 cals = 600 cals of carbs)
  • 30% Fat -  (30% of 2000 cals = 600 cals of carbs)

If you’re an endurance athlete you’d probably go the other way and consume a whole lot more carbohydrates to keep your body at it’s best while keto dieters replace much of their carb intake with fats and protein thanks to their satiating powers.

A few handy pointers to help you tweak your macros:

  • If you find yourself feeling hungry all of the time, replacing some of your intake with protein or fibre can make a big difference.
  • If you’re struggling to lose weight, try reducing your carbohydrate intake.
  • Sugar cravings can mess with everything! If you’re struggling it’s recommended to try cutting artificial sugar out entirely, as this can help combat the addictive properties of sugar.
  • If you’re losing muscle mass, increase your protein intake, just remember you have to keep exercising!
  • If you’re feeling fatigued, you might need to increase fibre intake as fibre plays an important role in energy conversion.  Increasing fibre intake has been shown to offer a number of health benefits too, so it’s probably worth doing!

The takeaway: Don’t stress too hard…

Counting macros can be really beneficial for many of us, whether it’s improving our health or reaching a certain level of fitness. However, monitoring your macros day-in-day-out might have a negative side if you don’t use the information well.

Focusing only on macros can make you think it’s easy to simply eat rubbish. Sure, those three donuts you pop every afternoon might fit your macros, but they probably don’t benefit you or your body when considering the broader side of your nutrition. Basically, don’t forgot that counting macros will only benefit you if you’re making sure to eat good quality food!

Lastly, don’t get obsessional. At Oatein we LOVE food. That’s why we do what we do. It’s ok to enjoy food, enjoy ‘cheat’ meals (arguably calling a meal a cheat meal is a bad move) and don’t let your diet cause you stress.