When it comes to Carbohydrates, most people don’t know where to begin. There are so many buzzwords being thrown around nowadays: simple/complex, fast release/slow release, sugars, blood sugar levels, starch etc. it is hardly surprising that we are all getting confused!

I have written this article to try a bring a bit of clarity to the situation, so that in future, you can make smarter decisions when deciding what to eat.

First, let’s get through a LITTLE bit of background science…

What are Carbohydrates?

Simply put, everything we consume can be split into two groups: Micronutrients and Macronutrients.

Micronutrients, we consume in very small amounts (micro), and are made up of vitamins and minerals, whilst Macronutrients we consume in large amounts and they are made up of three food groups: protein, fats and carbohydrates.

Carbohydrates (carbs) are chains of sugar molecules, and there are two types: Simple carbs and Complex carbs.

Simple carbs are chains of sugars, only a few molecules in lengths and can usually be broken down into single sugar molecules very quickly. They are usually found in foods with a distinctly sweet taste such table sugar, fruits, milk, sweets, and syrup. Generally, they’re digested very quickly, they give us a quick burst of energy and our blood sugar levels are driven up very quickly. The sugars in our blood stream are broken down and stored in our liver and muscles. Unfortunately, our liver and muscles can only store a limited amount, so the rest of these blood sugars are stored as fat.

Complex carbs are long chains of sugar molecules found in fibrous starchy foods like Pasta, potatoes, rice, bread and porridge. They are generally slow releasing; meaning we extract the energy from these foods gradually throughout the day, meaning they do not increase our blood sugar levels as quickly.  Therefore, we are less likely to store Complex carbs as fat.

Easy then! No more simple carbs and complex all the way, right?

Unfortunately, it is not quite as simple as that. (No pun intended)

Scientists have found that whether a carb is simple or complex doesn’t tell the whole story, and isn’t a reliable way to choose the carbs you eat.

Some complex carbs are actually fast releasing, raising blood sugar level s up quickly and thus promoting fat storage (white bread for example), whilst some simple carbs (for example, bananas) are actually slow releasing and don’t cause a dramatic increase in blood sugar levels.

I know, I have probably just made you more confused than ever! But stick with me it gets easier…

Luckily, some clever boffins have come with something called the Glycaemic Index, which tells us exactly how fast our blood levels rise after eating carbohydrates.  It ranks foods with a number, which classifies whether the food has a low, medium or high Glycaemic Index (GI).

Foods with 55 or less are classed as having a low GI, 56-69 have a medium GI, whilst 70 and above have are classed as high.

For example:

Bananas (which is a simple carb) have a GI of 52 so would be classed as having a low GI. This means that the energy in bananas are slow releasing and wouldn’t cause a dramatic rise in blood sugar levels, and are therefore less likely to be stored as fat.

Whilst white bread (a complex carb) has a GI of around 70-80 (high GI), meaning fast releasing and much more likely to be stored as fat.

So the Glycaemic index can help us choose slower digesting carbs, meaning that the carbs you’re eating are much less likely being stored as fat.


Another reason to cut down on fast digesting carbs (if getting fat wasn’t  reason enough), is we get very hungry, very quickly after eating them. When we eat fast releasing (high GI) carbs, our blood sugar levels are driven up quickly, when this happens our body releases insulin, which stores the sugars into our muscles, liver and as fat very quickly. When this happens our blood sugar levels drop dramatically, and this causes our body gets a huge craving for more carbs so that it can bring blood sugars back up to a stable level.

So shortly after you have eaten carbs, you get really hungry, so you eat more sugary carbs and the same thing happens: Blood sugar levels are driven up and then they drop dramatically, this makes you hungry again so you eat more sugary carbs and your blood sugars are driven up and then they drop dramatically, this makes you hungry again so you eat more sugary carbs and your blood sugars are driven…

You can see where I’m going with this, it’s a vicious sugar-craving cycle where the more carbs you eat, the more carbs you eat, the more carbs you eat…

To stop yourself turning into the Cookie Monster, stick to slower releasing carbs (low GI), as they regulate your blood sugar level much more consistently, so will keep hunger levels down and help reduce your sugary cravings.


So, when it comes down to making smart decisions when it comes to carbs, concentrate on the Glycaemic Index of foods, rather than whether it is simple or complex. Some foods have the GI value on the label, if you are unsure you can always google the food name + glycaemic index (e.g. brown rice glycaemic index) and you can find out the GI.

You can also use common sense when it comes choosing your carbs; you can generally figure out whether it is a good quality carb by asking this question:

Is it highly processed?

If your answer is yes, then it’s pretty much guaranteed it is no good for you and probably has a high glycaemic index. For example, white bread, bagels, most cereals, sweets, cakes, biscuits, fizzy drinks, alcohol etc. are all highly processed and consequently have a high GI. Conversely, whole, unprocessed foods e.g. fruit and veg, brown rice, brown pasta, wholemeal bread, oats have a lower GI so are a much better choice when for your general health and fat loss (They are also packed full of nutrient rich goodness).

With any luck, you are not hopelessly lost anymore when it comes to the subject of carbs, and you should now be able to make smarter decisions when choosing the things you eat.

However, as with anything, try and limit how much carbohydrates you eat (even if its low GI), as eating too much of anything will make you fat!