Putting The Kibosh On 'Carbophobia': Part One


Let’s face the facts, there’s nothing better than carbohydrates. Think freshly baked bread, fruit salads, brownies... they make you feel warm and fuzzy on the inside, the ultimate comfort food. So why a sudden rise in the number of "carbophobes" in the world? Personally I believe the media, *cough* closer magazine *cough*, celebrity endorsement and miseducation have a lot to answer for. The influential Kim Kardashian West recently posted a tweet stating 'No carbs. Crazy workouts. Whos with me?'. It's a no from me.



Fad diets are another pet hate of mine. I’m sure many of you have heard of the Atkins Diet. A diet revolving around low carbs for ‘fast results’. At first you feel great because you’re losing weight (may I just add this is mostly water and lean muscle), brilliant. But then the lack of glucose to your brain turns you into a complete non-functional zombie. Eventually you give up, most likely putting the weight back on and as soon as you know it you’re hunting down the next quick fix (perhaps the cabbage soup diet?). The phrase ‘yo-yo’ dieting comes to mind.

Please, don’t be part of the yo-yo brigade. Let me tell you the truth about our little misunderstood friend, the carbohydrate, through the wonderful world of science. In part one we will cover what carbohydrates are, the structure of these little guys and what foods you can find them in. In part two we will cover utilisation and why carbohydrates are essential in your diet! Lets get started! :)


Biochemistry of Carbohydrates

First thing you need to know is that we group carbohydrates. We've got the simple carbs and the complex carbs and their biochemical structures vary. They are composed from three elements: Carbon (C), Hydrogen (H) and Oxygen (O). You could call them ‘the ingredients of life’ or imagine them as LEGO blocks. The basis of every living thing comes from these tiny little guys – pretty crazy when you think about it. 

There are three major size classes of carbohydrates: 
monosaccharides, oligosaccharides and polysaccharides - "saccharide" derived from the Greek word sakcharon meaning "sugar".

Simple Carbohydrates - 'Instant energy'

Simple carbohydrates consist of single sugar units. Monosaccharides are the smallest of the carbohydrates containing 3-7 carbon atoms which can be bound to hydroxyl groups (OH = 1 oxygen + 1 hydrogen).  These atoms vary in the way they are arranged into a molecular structure, this is known as stereochemical configuration. They are vital fuel molecules and fundamental for all living organisms. Carbohydrates are so versatile - DNA is built on simple carbohydrates (deoxyribose)!

The smallest monosaccharides are composed of only three carbon atoms, on
e example is dihydroxyacetone. They are referred to as trioses, simply because they have three carbon atoms. Simple monosaccharides with four, five, six and seven carbon atoms are called tetroses, pentoses, hexoses and heptoses, respectively. 
Glucose and fructose are perfect examples of hexoses you will be familiar with. Glucose is an essential energy source for us and fructose is a common sweetener that is converted to glucose within our cells. Another common monosaccharide is galactose found in foods made with dairy-derived ingredients.

Complex Carbohydrates - 'Slow releasing'

In contrast, complex carbohydrates consist of two or more sugar groups (i.e two glucose molecules joined to form maltose - a dissacharide) or if we are getting fancy 'monomers'. You could think of these as pearls strung together on a necklace, where each pearl is a monosaccharide. Lets start with disaccharides.

Disaccharides are exactly what they say on the tin. Di (two) saccharide (sugar) = two sugars linked together. Remember I told you that carbohydrates were found all over the place? Well, lactose is a dissacharide found in milk. It is formed by the linkage of galactose and glucose, two monosaccharides. Let's use Sucrose, another disaccharide, as an example of how these carbohydrates join together...

Below are the chemical structures of glucose (left), fructose (middle) and sucrose (right). I know you're probably freaking out because these look confusing but remember the lego building blocks I was talking about? Here they are. The molecular formula for glucose and fructose molecules is C6H12O6. Meaning there are six carbons, twelve hydrogens and six oxygens. But as you can see it's their stereochemical configurations that differ. The molecular formula for sucrose is C12H22O11 - This makes sense as we have two monosaccharides, so their C, H and O's are added together. You may notice that if you add these together you get 24 H's and 12 O's, let me tell you where these have disappeared to...

The chemical reaction above is known as dehydration, which is a pretty easy concept to get your head around. A hydrogen (H) from one carbohydrate and a hydroxyl (OH) from another are taken out, in this example the hydrogen is from the glucose molecule and the hydroxyl the fructose (seen in black). As a result there are now two hydrogens and one oxygen, forming water (H2O). The glucose and fructose monomers are then linked together through glycosidic bonds - a type of covalent bond that joins a carbohydrate to another molecule, which may or may not be a carbohydrate (in this post we're focusing on just carbs). The process of dehydration applies to all carbohydrates. Another key process is hydrolysis. Essentially it is the reverse of dehydration. Water is added to a molecule to break it down. When dehydration synthesis continues oligosaccharides and polysaccharides are formed.

Oligosaccharides contain 3-9 monosaccharides and once they form long polymeric oligosaccharides (10+ monomeric units), via dehydration, they are deemed polysaccharides. These are vital for energy storage. 

Polysaccharides can be further categorised dependent on whether all the monosaccharide units are the same (homopolysaccharide) or two or more different units (heteropolysaccharide). The most common homopolymer is glycogen, made up of only glucose. Glycogen is stored within muscles and the liver for when it is needed – think how important this will be during exercise.

Examples of polysaccharides

Glycogen has already been mentioned but most of the carbohydrates that we ingest are starches. They can be found in foods such as grains, some fruits, vegetables, legumes, nuts and seeds. During digestion these are hydrolysed (broken down) by an enzyme known as α-amylase secreted by salivary glands in the mouth and pancreas. Fiber, which gives you that full feeling, has been shown to lower cholesterol and lower risk of high blood pressure. Cellulose, the most abundant organic polymer on earth, is an insoluble fiber (does not dissolve in water) and can be found in flour, bran, nuts and veggies. Gums, found in oats, legumes and barley, and pectin, found in apples, citrus fruits and carrots, are both examples of soluble fiber (dissolves in water). For more on fiber relating to health click me! :)
If you want to see the structures for different examples of both simple and complex carbohydrates illustrated in an easy to follow video click here.

What foods am I in?

A few examples have already been mentioned but I have created a 'carbohydrate cheat sheet' which has more. It is not a definitive list of all the carbohydrates in the world, but a little something to help you on your way to making more educated decisions on what you're eating. Hopefully now you understand the basis of carbohydrates. We have skimmed over what happens to these little guys in your body - more on utilisation in part two.

I think its great to understand how different foods affect our bodies. Simple sugars are broken down quickly so can be used for what I like to call 'instant energy', i.e post workout to refuel energy depleted muscles (don't forget your other macros :P). Complex carbohydrates provide 'steady energy' as the body takes longer to utilise them meaning they are ideal for breakfast. Although the body cannot differentiate between a can of coke and a piece of fruit it is essential to note the nutrient difference between them. This is where I make the point that low-carb diets are probably not the best idea. Yes, you may be cutting out more 'junk food' but you are also missing out on essential nutrients to keep your body working efficiently. I personally feel the best idea would be to moderate fizzy drinks, cakes, crisps, white bread (you get the picture) and to focus on consuming more fruits, veggies and whole grains, all of which keep our bodies healthy!

In my next post I am going to tell you how energy is produced from carbohydrates and what happens when you don't get enough of them (I like to call this zombie brain). Any questions please do not hesitate to comment below :)
References:
Biochemistry, seventh edition. Jeremy M. Berg, John L. Tymoczko, Lubert Stryer.
Encyclopedia of Foods, A Guide to Healthy Nutrition. Inc. Experts From Dole Food Company.

*Disclaimer: I am a third year Biomedical Science student. The information within the article is to the best of my knowledge with the above references used.


12 comments :

  1. This was so interesting! Really well written, you're very talented xxxx

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    1. Very sweet of you. Glad you enjoyed reading, thank you x

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  2. I personally eat more carbohydrates than any other food group, definitely not a carbophobe! The cheat sheet is very good :) From now on, I will call my daily apple a "simple carbohydrate". Simples!

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    1. Carbohydrates are yummy :P All about moderation!!

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  3. Found via your twitter account! Wondered if you had ever been on a low carb diet? I liked how this is different from other nutrition and fitness blogs where there is no basis behind their posts, this has a great scientific background. Easy to take in. Really looking forward to the next one.

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    1. Aww thank you! I have been on a low carb diet, although it had its pro's it made me feel horrible, concentration was low, I had no energy. Seriously would not recommend haha.

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  4. Finally the truth about carbs. Sometimes I am so disenchanted with social media, but you have helped me believe again!

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    1. Michelle, I feel EXACTLY the same, it's very difficult to find the truth amongst all the fad diets and incorrect information on social media platforms. I've only just started this blog but I am hoping to provide a place where people can find information with a correct scientific basis that's easy to understand :) Thank you for reading and commenting.

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  5. Kind of sad, that Social Media outlets, have such an impact on people's everyday lives. So muhc banter and back and forth going around, people can't seem to pick one and run with it. So much useless information being brainwashed into people's minds, to make them think, they are doing the "right" thing. Not a fan of Social Media, and don't read too much into anything. I see something here, that can change people's perspectives on not only diets, but what goes in our mouths, eating right, cooking right, and also giving a new light on people who can actually say "I feel amazing today". Keep it up.

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  6. If you need any contributors to the site. I am well versed in health and nutrition. Personal trainer and coach. I don't mind helping you out.

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