Macros: An intro to carbs

Carbohydrates are a polarising subject, historically they have been pontificated and, more recently, vilified in the press and by “experts”. It is hard to know what to believe, what you should and should not be doing when it comes to nutrition. Here I’ll try to introduce a few truths and outline a couple of basic differences between types of carbohydrates.

Figure 1 The broad range of foods that supply carbs within our diets

Carbohydrate is a macronutrient that is usually split into two distinct categories, simple carbohydrates (SC) or complex carbohydrates (CC). A SC is a sugar based carb which can be broken down quickly by the body to be used as energy, these are the carbs responsible for the “sugar-rush” where you get a spike of energy soon after consuming them, but often get the dip after the rush has peaked. These can occur naturally, and those natural SC will be in the form of sucrose, lactose or fructose (there are other ways to sub-categorise these but we'll keep it simple). The modern diet gets most of its SC from more processed foods, added sugars that are used to improve taste or help to preserve the food so they last longer in our cupboards or fridges. It's important to note the SC can occur naturally, and they are the types of SC useful for optimising health.


The other form of carbs in our diets are CC which occur naturally and take longer for our bodies to digest. This ensures that the energy you gain from eating these types of carbs is released slower and, therefore, results in a lower but more sustained peak of energy and are not associated with the sugar dip that occurs after SC consumption. In general, we should aim to eat the majority of our carbohydrate intake from sources high in CC as they have profound benefits around the body.

Figure 2 Foods high in sugar

Body composition

Where you get your carbs from can have significant effects on your body composition, as the quick energy released from SC will ultimately be stored as fat if it is not used quickly. It is the benefit of having something higher in sugars when you need an energy boost, but make sure that this energy is being used otherwise there is a good chance it will be stored as fatty-tissue. This is an area where CC has an advantage over SC, as they are digested more slowly and, therefore, release its energy over a sustained, longer period of time which means you do not get the rush of energy into your body which must used quickly, which occurs with SC consumption. Instead, you can use it a lower rate over a longer period and therefore you will not crave more energy as quickly like when you load up on SC.



It is well evidenced that high intakes of SC will result in higher levels of insulin, making the insulin work harder to turn the quickly available sugar into energy. If consumed excessively it can lead to issue with insulin-resistance, where the cells in your body start to reduce their response to insulin and therefore struggle to utilise the glucose in your blood. The response? Creation of more insulin from your pancreas which is done to help glucose enter the cells. If SC are consumed excessively over a long period of time there is a chance you simply won’t be able to produce the amount of insulin required to overcome the cell’s weak response to glucose… This is when Insulin resistance truly occurs and blood glucose levels rise. This is linked to a number of chronic health conditions, but the good news is that if recognised early enough there’s a good chance it can be reversed.


Starch found in CC can be categorised in a few different ways, we will concentrate on foods rich in slow digesting starch, called Amylose. We’ll stick with insulin here, and what’s important to note is that CC rich in amylose have the opposite effect on insulin that SC has. It can help to improve insulin sensitive whilst having extremely positive effects on structure and function of the gastrointestinal tract.

Figure 3 Examples of foods high in starch


In reality this post could go on and on, so I’ll stop there and revisit it another time. What I hope is evident is that there is a significant difference in types of carbohydrate. I’ve only outlined a couple of differences, but both of which have profound impacts on chronic health and function, it’s certainly not rocket science but I think understanding just howSC and CC affect you differently can have an impact on your selection of food sand help you to make informed decisions as to what to eat and when to eat it, and if you make sub-optimal choices then knowing why your feel the way you feel is no surprise which can be very helpful.


Many thanks for reading




Coming Soon

You'll be able to find out a lot more about carbohydrates from our Production Education resource, helping you gain the knowledge to own your nutrition.