Macronutrients: Carbohydrates

In my previous post I talked about the basics of nutrition and what a “healthy, balanced diet” should consist of. However, there is more to it than that- all of the foods we eat can be categorised into three main food groups or MACRONUTRIENTS. These are carbohydrates, protein and fat. Each come from different sources, serve different functions in the body and you have varying requirements for them. I’m going to discuss each of them separately to hopefully help you understand exactly what you are eating, how much you aim for and why.

Let’s start with the big one: Carbohydrates

Function: Despite what you may see in the media, carbs are not the devil! They are our bodies PRIMARY and PREFERRED energy source. We NEED carbohydrates to carry out basic bodily functions and to fuel our daily activities. All body tissues require a constant supply of glucose to function. So, when you’re eating your oats at breakfast, it not only provides fuel for muscles for your upcoming workout, but your body uses the carbohydrate to feed the brain and your central nervous system- both of which are pretty important!!

Structure: Scientifically speaking they are long chains of carbon, hydrogen and oxygen atoms. They can be classified by their structure starting with monosaccharides (mono= one). These are made of only one molecule and are the simplest form of carbohydrate e.g. glucose. Next are disaccharides, which are made when 2 monosaccharides join together (di= two...makes sense hey?!) e.g. lactose. Then we have polysaccharides (poly=many) which are made up of several molecules of monosaccharides, such as starch. There are also Oligosaccharides which are carbohydrate molecules that have longer carbon chain lengths than mono and disaccharides, but are shorter than polysaccharides. They have carbon chains of between 3 and 10 carbon molecules. Generally, humans do not have enzymes to digest oligosaccharides so they pass through the digestive tract and may be metabolised by gut bacteria. Sorry, if that was a lot to digest (pun intended).

Carbohydrates may also be classified into dietary categories according to they are broken down; simple/sugars and complex/starches. Simple carbohydrates have a branched structure and when they are broken down each “branch” provides energy quickly. Complex carbs have a straight chain of molecules meaning it takes longer for the chain to be broken down to release its energy. Included in the complex group is NSP (or non starch polysaccharide) which cannot be digested in the small intestine so these provide fibre (to keep you regular!)

Sources: Almost all foods contain carbohydrates, but here is a list of some of the most common ones:

Simple: sugar, honey, jam, fruit, cakes, biscuits, diary, sweets etc..

How much? Government guidelines recommend carbohydrates should make up 50-55% of our daily calorie intake. This can be further broken down to 45% coming from starchy carbohydrates and 5-10% from sugars.

What does this mean in food terms? So if you were to go on the basic value of 2000 calories a day, this would mean around 1000-1100 of your calories should come from carbohydrates. Given that carbohydrates have a calorie value of 4 per gram this means you should aim to eat around 250-275g of carbohydrate per day.

Here is how you should try to plan your carbohydrate intake around your training. The GI of a food (glycaemic index) is basically how quickly it is absorbed (I shall cover this on another post!) Foods with a high GI value are quickly absorbed (ideal for a quick energy boost or refuel) and low GI foods release energy slowly.

Have a look at the table below as to what is recommended for your body weight and activity level (taken from Future Fit Nutrition for Sport and Exercise)

Here is how you could try to plan your carbohydrate intake around your training. The GI of a food (glycaemic index) is basically how quickly it is absorbed (I shall cover this on another post!) Foods with a high GI value are quickly absorbed (ideal for a quick energy boost or refuel) and low GI foods release energy slowly.

You may now be wondering what the heck 50g of carbohydrate even looks like?! So here are a few more examples:

1 bagel

3-4 Weetabix

3 crumpets

70g uncooked pasta

175g jacket potato

2 medium bananas

70g raisins

6 Jaffa cakes

So there you have it. CARBS ARE NOT THE ENEMY. We NEED them to function.

Hopefully you can apply the recommendations to your own diet and training. You may be surprised at how much you actually need to fuel your body! And if you already knew it, it’s just given you even more of reason to eat Jaffa cakes!

#carbohydrates #nutrition #macronutrients #healthyliving #foodisfuel