Nutrients are substances needed for growth, energy provision and various other body functions.


You may have heard the term macronutrients before, particularly in the bodybuilding world, often shortened to “macros”.


But what are they?


Macronutrients are simply protein, carbohydrate and fat. They are called macronutrients as they are required in large amounts to feed the body; they are each required for specific reasons which I will expand on later.


Micronutrients refer to vitamins and minerals which are required in much smaller amounts (in terms of weight per nutrient) which are required for many functions within the body.


This article will give you a brief introduction to macronutrients and give you a basic understanding of what macronutrients I recommend.


Let’s start from the beginning.


What is a carbohydrate? 


In scientific terms a carbohydrate is a compound that consists of carbon, hydrogen and oxygen (Which is why you sometimes see carbohydrates expressed as CHO). 


Furthermore carbohydrates are often classified into many categories by various different people; simple and complex carbs, high/medium/low glycemic index/glycemic load carbohydrates, starches and sugars and so on. 


Carbohydrates are a very highly debated topic at the moment; many people argue that high carbohydrate diets are largely to blame for weight gain/obesity however the government guidelines state that the majority of the calories in our diet should come from carbohydrates. 


But that is a long topic for another day.


Essentially carbohydrates are an energy source which you no doubt already know but do you know how different carbohydrates can affect you?


Without going into too much detail I will explain how carb sources differ.


In my opinion the biggest factor to consider when choosing a carb source to eat/drink is the glycemic index. 


(The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. 


Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. Low-GI foods, by virtue of their slow digestion and absorption, produce gradual rises in blood sugar and insulin levels, University of Sydney)


If you are consuming carbs throughout the day then you should opt for low GI foods to avoid a slump in energy. High GI foods should be consumed after exercise to replace glycogen and to aid the uptake of nutrients into the muscle cell. 


It may be worth “googling” what the glycemic index is of carbohydrates you regularly eat. 


These are the carb choices I recommend


Sweet potato

White potato

Brown rice

Basmati rice

Jasmine rice

Rice cakes

All vegetables (green veg in particular)

Fruit (be conscious of a high fruit intake)

Carb powders for PWO shake (maltodextrin, dextrose)



Personally I only use carbs PWO/last meal of the day as I feel better following a high fat/high protein diet, but this is individual.



What is protein?


Proteins are large molecules made up of amino acids which are required by the body for optimal function. There are 20 different amino acids which are combined to make millions of different proteins, each with a specific function in the body. Some of the main functions of proteins in the human body are


  • Build, strengthen and repair tissue
  • Muscle contraction (actin and myosin for those sport scientists)
  • Make enzymes to improve biochemical reactions
  • Make antibodies for our immune system. 


Many people would agree that a high protein diet would be suited to any person looking to improve body composition. 


For strength/power based athletes as well as bodybuilders then a general rule for protein intake is 2g per kg of bodyweight. Intake above this has not shown any benefit but will have a financial impact as protein sources are not cheap.


For the majority of people looking to improve body composition then I would recommend a minimum of 1.2g per kg of bodyweight. 


What protein sources are there?


There are many protein sources that can be used within the diet, the following are some of my favourites especially when considering a budget


Lean beef mince

Whole Milk

Whole Chicken

Tinned mackerel/herring (avoid sunflower oil due to reduced omega 3 ratio)


Cottage cheese

Whey protein

Eggs (yolks included!)


What is fat?


Before I go on to introducing fat I want to make one thing clear. 




Fat is essential for optimal health and makes up a large percentage of my diet. 


Body fat and dietary fat are completely different. 


Fat is a nutrient. It is vital for normal body function and without it we would ultimately not be able to survive. 


Another issue that needs to be cleared up immediately is that not all fats are the same; there are various different types of fat. But before I expand on that I’ll explain why fat is important.


  • Fat provides us with an excellent energy source 
  • Fats form structural material of cells ad tissues e.g. cell membranes
  • Fats transport vitamins A,D,E,K in the body as they are fat soluble vitamins and cannot be poorly without it.
  • Good cardiovascular health
  • Fat is essential for hormone support 


Fat contains 9Kcal per gram which is double the amount of protein and carbohydrate (4Kcal) so when looking to drop body fat then fat seems like the sensible macronutrient to drop as it contains more calories? 


This is absolutely not the case, fat must remain in the diet for all of the reasons above, it can be reduced to a baseline if really trying to reduce calories but it should not be cut out. 


As mentioned there are different types of fat; monounsaturated fat, polyunsaturated fat, saturated fat and trans fat.


For me to go into each type of fat would make this article extremely long but I will give examples of food sources for each type of fat.. 




I’ll start with trans fat as there is no debate that these have a negative impact on health. They are formed during “hydrogenation”, this helps to keep oils solid and stable at room temperature for use in foods to preserve shelf life in foods. 


Trans fats are in many processed foods and should really be kept a minimal (ideally none) in the diet.


Top culprits (no surprises here)


  • Fast food
  • Margarine 
  • Cookies
  • Processed frozen food – pies, breaded foods etc
  • Crisps and crackers
  • Baked foods – doughnuts, pasties, cakes etc


As always, I am never saying don’t ever eat any of these because that’s not realistic for 99.9% of the population but these really should only be a “treat” and not part of your regular diet.


Trans fats are completely banned in Austria and Iceland!! 


Polyunsaturated fat foods


  • Fish (Salmon, mackerel, herring, trout, fresh tuna
  • Flaxseeds, walnuts and oils
  • Legumes and seeds


Monounsaturated fat foods


  • Oils (olive, peanut, canola, sunflower, sesame)
  • Nuts
  • Avocado
  • Olives
  • Seeds


Saturated fat foods


Mainly animal products

  • Meats (fatty portion of various meats)
  • Dairy (butter, milk, cheese, yoghurt
  • Coconut/coconut oil


These are the main fat sources I recommend 


Kerrygold butter (grass fed butter, good source of medium-chain triglycerides)




Coconut oil

Olive oil (not cooked, used at room temperature)




This article ended up a lot longer than I wanted and took longer than I wanted to write due to trying to keep everything as concise as possible. Many of you may already know everything I have written here but this was just a brief introduction to macronutrients. Future articles on macronutrients will be in more detail, how they are used within the bodybuilding world and how you can manipulate them to suit your goals.


Direct all questions to @bencullen_ on twitter. 



















6 thoughts on “Macronutrients.. A true beginner article

  1. Pingback: Macronutrients .. A deeper look. | Beginner Nutrition

  2. Pingback: “Meal of the week” 4 | Beginner Nutrition

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