Facts on Sugar
Updated: Jan 26, 2021
This week has been sugar awareness week. A week designed to inform the public about the health effects of consuming too much sugar in our diet. It also focuses on encouraging the food and beverage sector to decrease the amount of sugar present in the foods we eat and encourage the government to implement public health policies to help us reduce the amount of sugar we eat.
But why does sugar have such a bad rep? What are the health implications associated with eating too much sugar? Are there really ‘healthy’ sugar alternatives? And is sugar really as addictive as these health and wellness promoters seem to be telling us?
First up, what is sugar and in which foods do we find it?
Sugar is the simplest form of carbohydrate. It comes in many different types including glucose, fructose and sucrose. It’s these simple carbohydrates, also known as monosaccharides and/or disaccharides, that give our food the sweet taste.
Glucose is an extremely important molecule as it’s our primary energy source for our cells. It is also the molecule that when joined together forms glycogen – the main way we store excess energy ready for when we need it. Glucose is found in some fruit and vegetables and is readily absorbed in our small intestine; then straight into our blood stream.
Fructose is the most common simple sugar found in fruit and vegetables. In contrast to popular beliefs, fructose is absorbed slowly into our blood stream and is then transported to our liver where it is converted into glucose.
Sucrose is actually a disaccharide, meaning it is made of two simple sugars bonded together: glucose and fructose. Sucrose is also commonly referred to as table sugar and is the sugar most commonly added to processed foods and sugary drinks.
Lastly, lactose. Lactose is also a simple sugar which is only found in milk…yes milk contains sugar! It makes up about 4.7% of cow’s milk.
Refined vs. unrefined sugar
Refined sugar is sugar which has been processed into white table sugar that we come to think of when we think of sugar. Refined sugar is most commonly added to foods such as this includes fizzy drinks, sweets, biscuits, cakes and yogurts.
The reason why refined sugar is marketed as being particularly bad for us is owed to the fact that when sugar cane and sugar beet is processed, it strips all the other nutrients away such as the vitamins, minerals and fibres. This means that white table sugar is very energy dense (high in calories) with no nutritional benefit.
Unrefined sugars are those that are found in fruits and vegetables, as well as in honey and coconut sugar. Hence these sugars are often referred to as being 'healthy'. They have undergone less processing meaning that they still retain some other nutrients such as minerals, vitamins, and some fibre.
Not all sugar is the same
Although fruit and vegetables contain sugar, they are not considered to be bad for our health. This is because these foods also contain many other vital nutrients such as minerals, vitamins and fibre.
We are more concerned about what we call free sugars. Free sugars are those that we add to foods such as fizzy drinks or yogurts, sugar used in cooking such as baking cakes and ones which are found in fruit juices. This also includes sugars such as honey, coconut sugar and agave syrup, which we are led to believe by some health and wellness influencers as ‘healthy’ version of sugar.
The sugar that is present in fruit juices is classed as free sugar even though it originates from whole fruit, as it is no longer bound up in the cell walls of the fruit. This means that it is much more easily digestible, we are more likely to eat more of it and it does not contain the other nutrients which are also present in whole fruits or vegetables such as fibre.
But hang on a minute, I know what you are thinking, honey and coconut sugar are what we call unrefined sugar, aren’t they the type of sugar we should be eating?
MYTH BUSTER: Honey and coconut sugar are still sugar. Despite the fact that both honey and coconut sugar contain more minerals and vitamins than table sugar, this amount is so small that the detrimental effects of consuming too much sugar in our diet outweighs the tiny amount of mineral and vitamins which may be present. So basically, these sugars are no ‘healthier’ than normal table sugar.
How much sugar is too much?
The recommended daily intake of free sugars in the UK is currently 10% of the total daily energy intake. This equates to about 30g of free sugars per day . There is also a strong recommendation from the government advisory committee that this should be reduced to 5% of our total daily energy intake due to the detrimental effects that consuming too much sugar can have on our heath (I’ll get to this later!).
As a nation however, on average we consume much more than the 5% recommended amount. For example, sugar intake for school aged children and teenagers is around 15% of their total daily energy intake, and for adults this is only a little less, around 12% of our daily total energy intake .
The main sources of this sugar intake comes in the form of soft and fizzy drinks, fruit juices, biscuits, cakes and breakfast cereals. For children aged between 11 and 18, soft drinks are the main source of their sugar consumption, equating to around 30% of their daily sugar intake .
It is clear therefore, that as a nation we do consume too much sugar. It can be relatively easy to decrease the amount of sugar we consume by making some simple, small changes. For example, choosing a soft drink with less sugar content, only drinking one glass of fruit juice a day, and not adding sugar to our tea or coffee.
Health effects of eating too much sugar
As you can see, there are many sugars that are found in foods which are described as healthy and essential for development (milk). So why are we so concerned about the amount of sugar we are eating?
Both tooth decay and obesity have been linked to diets in which people consume high amounts of sugar. Let’s delve a little deeper and look at the evidence behind these claims.
Sugar and tooth decay
High sugar intake by both children and adults has been linked to increased tooth decay. There have been many observational studies conducted looking at the effect of tooth decay in relation to the amount of sugar consumed. The majority of evidence demonstrates that decreasing sugar intake to less than 10% of our total daily energy intake decreases the risk of developing tooth decay.
A meta-analysis (a type of study that analyses findings from many different studies), also determined that reducing free sugar intake to less than 10% of total energy intake reduced the amount of tooth decay .
It was from these studies that the World Health Organisation published their recommendations that no more than 10% of our total energy intake should come from sugar. However, as I mentioned above on average in UK, we consume a lot more than this!
Sugar and obesity
Over the last 10 years there has been increased public health awareness over the link between high sugar intake and obesity. It is thought that consuming high levels of sugar leads to weight gain, which may eventually, overtime lead to obesity. Obesity is associated with other health complications and diseases such as type 2 diabetes and coronary heart disease, therefore high sugar intakes have also indirectly been linked to these diseases too.
DISCLAIMER: consuming sugar will not make you gain weight! To put it simply, if we consume more energy than we burn over a prolonged period of time then yes, we will inevitably gain weight. However, it’s not just sugar that will do this. it is our diet as a whole that will determine our overall energy consumption and hence whether we will gain weight or not eating one sweet or one chocolate bar will not make us fat!
There is a lot of emphasis on sugar and gaining weight, as sugar is often described as empty calories; meaning it has very little nutritional value but is highly calorific. Products such as fizzy drinks contain lots of added sugar without providing you with that satisfying feeling that you may get after eating a balanced meal. This has led to the notion that drinks and processed foods high in free sugars are fueling the obesity epidemic that we are seeing in the UK.
However, we must be aware that the evidence suggesting that eating lots of sugar causes obesity is very controversial. Some studies have shown that there is a direct link between high sugar intake and obesity  and others have found no link at all .
This contradictory evidence is most likely a result of the many other factors which can lead to obesity. These include our overall dietary pattern, lifestyle such as exercise and whether one smokes, as well as our genes which may make people more or less susceptible to developing these diseases. This therefore makes it very hard to determine whether consuming too much sugar directly causes obesity. Additionally, many studies which show no link between sugar consumption and obesity have been funded by soft drinks companies; it is in their interest for the outcome of the study to show no link between sugar intake and weight gain.
As ever in nutritional science, we need more robust, randomised control trials of both adults and children, to help determine whether solely sugar causes weight gain and is fueling our obesity epidemic. However, we must also reiterate that focusing on one nutrient is not always the best way forward; we should focus on our diets as a whole and refrain from focusing on just certain nutrients.
One more myth buster…
A question that I hear a lot and see many posts about on Instagram…is sugar addictive? Despite many people, including influencers and even TV presenters endorsing the fact that sugar is addictive, the jury is still out. There is insufficient evidence to say that sugar is additive.
The majority of the studies looking at whether sugar is addictive have been in animals, with very few studies being undertaken in humans. The studies which have been undertaken, do not provide strong evidence to support the effect that sugar can be classed as an addictive substance.
One of the arguments for sugar addiction is that when we eat sugary foods, the reward system in our brain lights up and there is a release of a chemical in our brains called dopamine. Dopamine is also released if we take cocaine and when we exercise, amongst other things. Therefore, this can’t be used as the sole reason to class sugar as being addictive.
It is also important to remember that our reward system in our brain lights up when we eat other foods. This is because in evolutionary terms, eating food is meant to be rewarding, if it wasn’t we wouldn’t want to eat again. This reward system is critical for us to be able to stay alive!
To sum it up, there is no solid evidence to suggest that sugar is addictive.
Take away messages
As a nation we must aim to cut down on our free sugar content.
High sugar intake is linked to increased tooth decay.
There are some links to high sugar intake and the increased risk of obesity, as well as developing obesity related diseases. However more research is needed as this evidence is controversial.
Not all sugars are the same.
Sugars marketed as ‘healthy alternatives’ (*cough cough* coconut sugar) are still sugar and will still have the same effects as table sugar, they just cost a lot more.
Sugar is NOT addictive.
AND don’t forget…
We shouldn’t restrict food groups in our diet. We should look at our diet as a whole not as individual components.
Sugar eaten in moderation is not a bad thing. Don’t stop eating chocolate if you love it, but maybe think about cutting down on your intake or opt for dark chocolate which has a little less sugar than milk chocolate.
Above all, let’s EAT HAPPY and LIVE WELL.
Bates B LA, Prentice A, Bates C, Page P, Nicholson S, Swan G. (Eds). (2014) National Diet and Nutrition Survey: Headline results from Years 1 to 4 (combined) of the rolling programme from 2008 and 2009 to 2011 and 2012. Online. Available from: https://www.gov.uk/government/statistics/national-diet-and-nutrition-survey-results-from-years-1-to-4-combined-of-the-rolling-programme-for-2008-and-2009-to-2011-and-2012
Moynihan P. Sugars and Dental Caries: Evidence for Setting a Recommended Threshold for Intake. Adv Nutr. 2016;7(1):149-156. Published 2016 Jan 15. doi:10.3945/an.115.009365
George A. Bray, Barry M. Popkin. Dietary Sugar and Body Weight: Have We Reached a Crisis in the Epidemic of Obesity and Diabetes? Diabetes Care Apr 2014, 37 (4) 950-956; DOI: 10.2337/dc13-2085
Richard Kahn, John L. Sievenpiper. Dietary Sugar and Body Weight: Have We Reached a Crisis in the Epidemic of Obesity and Diabetes? Diabetes Care Apr 2014, 37 (4) 957-962; DOI: 10.2337/dc13-2506