A Beginner’s Guide To Macronutrients

A  Beginner's Guide To Macronutrients

You can hardly talk about calories without talking about macronutrients, they’re so heavily intertwined that to understand one you must understand the other.

What Are Macronutrients?

Macronutrients, also known as macros, are your three main food groups and the source of the calories you need daily to not only survive but perform any activity you do.

The three macronutrients are;

  • Protein
  • Fats
  • Carbohydrate

There is also a fourth macronutrient but as it includes no nutritional value it’s often not included. This macronutrient is:

  • Alcohol

Now you might ask why macronutrients are so important if calories determine whether you gain, lose or maintain your weight.

The reason is because whilst calories do control your weight, macronutrients play a much greater role in your overall body composition after weight change;

  • Preserving muscle mass when losing fat
  • Minimising fat gain when building muscle

To understand how they do this we must look at the caloric value of each macronutrient along with the role they play in the body.


Protein provides four kcals per gram and is important for repair and maintenance of the body’s tissues including muscle mass. Protein also provides a longer feeling of satiety at meals.


Fat provides nine kcals per gram and is the most calorie dense macronutrient. It is important for the intake of fat soluble vitamins and hormone regulation amongst other things. Fat can also be used as a secondary fuel source in the absence of carbohydrate.


Carbohydrate, like protein, also provide four kcals per gram and is the primary source of energy for the body. It not only fuels the muscles but also the digestive system, brain and other important organ functions.


Alcohol provides seven kcals per gram but no nutritional value and when metabolised is actually toxic for the body. Learn more about the effects of alcohol here and here.

For more detail information on the role of macronutrients and performance, check out this post I wrote on it, here.

Now we know the role each macro plays in the body and how many calories they provide per gram, we need to look at how much of each one we need.

What Are Your Macronutrient Needs?

Each macronutrient plays an important role in the body and you need some of each to perform at your best, particularly if you’re training regularly.


The general consensus with protein is that your intake should be a slightly higher when eating in a calorie deficit to help preserve muscle mass and slightly lower for maintenance or muscle building.

But what is this amount?

Well, research (1) shows that a protein intake between 0.6 – 0.9 g per lb of bodyweight is adequate for maximising protein synthesis. This same study also recommends that eating closer the 0.9 g per lb mark may be advantageous for those eating in calorie deficit to help preserve muscle mass.


There is no doubt you need to include fat as part of your daily calorie intake, however, when training regularly and eating to maximise your results you’d be smart to eat enough fat to support overall health but not so much that you can’t maximise your carbohydrate intake.

The general recommendation and one I’ve used and given myself is to have approximately 30% of your daily calorie intake made up from fat.


There is a lot of controversy surrounding carbohydrate intake, particularly in relation to fat intake BUT when it comes to resistance training you can’t go wrong with a moderate to high carbohydrate intake.

Let me show you why.

Research (2) shows that glycogen stored in your muscles is the primary fuel source of moderate to intense exercise. Add to this research (3) that shows a sufficient carbohydrate intake that keeps your muscle and liver glycogen stores full can improve workout performance.

How To Calculate Your Macro Needs

Once you’ve decided your goal and calculated your daily calories you can then setup your macronutrients.

  • Protein = as protein is set by weight you need to multiply the protein amount (i.e. 0.8 g) by your weight in pounds. This will give you your daily gram amount.
  • Fat = calculate 30% of your daily calories then divide that number by 9 to get your daily fat amount in grams.
  • Carbs = take the remaining calorie amount after setting your protein and fat and divide it by 4. This will give you a gram number of carbs to eat each day.

Once you have your gram amount for each macronutrient you can enter them, along with your daily calorie goal into MyFitnessPal to track your progress.

Summing Up

There we have it, a beginner’s guide to macronutrients; what they do, why you need them and how much you need.

Call to Action

To help you on your fitness journey I’ve put together a training routine and nutrition cheat sheet for you to follow. Get your FREE copy by clicking here.