What happens to your body after eating sugar?

Experts reveal the shocking impact sugar has on our health, skin and mood
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  • Indulged in a can of coke? It's Sugar Awareness Week- and we reveal how it will effect your body and mind for the next 24 hours and in the long term.

    It’s no exaggeration to say that in recent years, sugar has become public enemy number one. There’s been an influx of TV shows, documentaries, articles and social media posts condemning the ingredient for all the ills it brings us, while also revealing just how much of it we’re exposed to every single day.

    Because although many of us were all well aware of the sugar in our doughtnuts, cakes and biscuits, some of us were less informed about just how sugar-laden some of our cereals, drinks, and snack bars were. And the reality is pretty shocking.

    In fact, the NHS advises that adults have no more than 30g of ‘free sugars’ a day – that’s added sugar and natural sugars (found in fruits and juices, for example) and is the equivalent to seven sugar cubes. But a recent survey reveals that almost all of us are exceeding that intake.

    The 2018 National Diet and Nutrition Survey revealed that adults between the ages of 19 and 64 were consuming around 58.8g of sugar a day – that’s almost twice the suggested intake. And, children – who should have no more than 24g – are having 60.8g of the highly addictive stuff per day. That’s almost three times the recommended amount.

    But it’s perhaps not surprising, given that a can of cola can contains 11g of sugar on it’s own, and an average glass of orange juice has around 8g.

    But just how far is this sugar over-consumption affecting us, and what impact is it having on every part of our body – from our skin to our heart?

    What happens immediately after eating too much sugar?

    Credit: Getty

    Your energy levels

    If you’re partial to dipping your hand in the biscuit tin or having a couple of sweet treats in the afternoon, the impact on your mood and energy levels can be immediate.

    Emily Freeth, a dietitian at The Hospital Group, revealed that an overload of sugar can be responsible for massive dips in energy throughout the day.

    She explained: “If you include too much sugar in one go the body finds it harder to regulate your blood sugar levels. Later on in the day you are at risk of decreased energy levels and feelings of fatigue and tiredness. This is why it is important to spread out sugars throughout the day, and have them in small amounts and alongside other food groups such as proteins.”

    The sugar crash

    So what about the infamous sugar rush? Isn’t that one of the good things about sugar – a quick boost of energy? Not so much, it seems. Dr  Daniel Atkinson, Clinical Lead at online pharmacy Treated, revealed that while the rush may be fun, it’s also always accompanied by a crash.

    “The sugar rush tends to come shortly after with increased dopamine levels in the brain – but so does the dreaded crash. Insulin and hormone levels have risen rapidly and caused blood sugar levels to drop. This sugar slump leaves you feeling tired, irritable and may cause headaches.” Not so good, then.

    Interestingly, our sugar consumption could also be affecting our immune system, and our ability to fight of disease and infection.

    “Because of how your body has had to treat the sugar binge, your immune system is not working at its peak.” And it’s not a quick fix either. “It can take up to five hours for the immune system to properly recover.” Dr Daniel told GoodtoKnow.

    Your emotions and mood

    And scarily, there’s also an instantaneous effect on our heart health, and on our brains – which in turn, impacts how we feel emotionally.

    “Just 30 minutes after consuming a lot of sugar, your heart rate will accelerate and you might begin to sweat, as epinephrine and cortisol are released by the body” Dr Daniel explained. “This is due to the renal system identifying the sugar influx as the body in stress.”

    Your teeth

    And while we might consider the damaging impact of sugar on our teeth to come over months and/or years,  explained that it’s actually pretty quick.

    He told GoodtoKnow, “Indulging in a quick fix of sugar affects your teeth and gums quickly, as an acid forms that attacks the enamel on your teeth.”

    What are the long-term effects of eating too much sugar?

    Credit: Getty

    Over the years, sugar can have a significant impact on our heart health, as well as exposing us to a range of serious diseases. Dr Daniel explained, “Long term effects of over-consuming sugar can lead to tooth decay, weight gain leading to obesity and diabetes.”

    Type 2 diabetes

    In fact, type 2 diabetes is caused almost exclusively by lifestyle factors – which can include a poor diet and lack of proper, healthy foods. He told us, “90 per cent of diabetes cases are type-2. While type-1 is caused by the immune system attacking the pancreas, type-2 is typically developed later in life, and several factors can contribute towards it, including diet and lifestyle.”

    And of course, type 2 diabetes isn’t easily fixed, and can in fact lead to other health issues. Dr Daniel said, “The condition impacts everyday life. Type 2 diabetes can also lead to other health issues like heart disease, vision loss and kidney problems.

    “Losing weight though will help significantly with type 2 diabetes so cutting down your sugar is advised.”

    Heart disease and strokes

    Obesity, and excess fat can of course lead to an increased risk of heart disease too – such as heart attacks and strokes.

    In a study published in 2014 in JAMA Internal Medicine, Dr. Frank Hu, professor of nutrition at the Harvard T.H. Chan School of Public Health, found a direct link between a high-sugar diet, and a greater risk of dying from heart disease.

    The survey, which took place over 15 years, found that people who got between 17% – 21% of their calories per day from added sugar had a 38% higher risk of dying from heart disease, compared to those who only consumed 8 per cent of their calories per day from added sugar.

    The link between the two is considered to be that sugar can lead to obesity and excess fat – and being overweight, it’s well documented – can put your heart at greater risk of cardio-vascular disease.

    What happens to your skin if you eat too much sugar?

    Alamy Stock Photo

    Alamy Stock Photo

    Your skin might not be the first place you expect to see the effects of sugar, but we all know that what you eat can come out in your complexion.

    Sugar and acne

    And it’s no different with sugar, In fact, according to skin and health specialist at Pure Optical, Tammy Richards, foods high on the glycaemic index can trigger inflammation and acne – and those foods include things like sugary fizzy drinks. She explained: “The glycaemic index refers to food that rapidly transforms into glucose once digested and in turn, raises the body’s insulin levels. This is known as the glycation process. It is the glycation process that results in inflammation of the skin and can trigger conditions such as acne.”

    But it seems that sugar could be affecting our skin in another way too, by reducing the function of our white blood cells. “White blood cells are responsible for combating infection. Their suppression paves the way to the perfect environment for acne as bacteria evolves within the layers of the skin,” Tammy explained.

    Sugar and ageing

    So, can sugar also affect how our skin ages? We’re all well aware of how our skin will change – or has changed – as we get older – so what affect can the white stuff have on it?

    Dr. Carl Thornfeldt, dermatologist and founder of Epionce clinical skincare, has asserted that: “refined sugar is the poison that drives all inflammatory (skin) conditions.” According to him, inflammation is one of the things that can damage our skin the most.

    “Chronic inflammation is one of the primary drivers behind many skin diseases and undesired skin conditions. Everything from acne to rosacea to skin cancer is triggered by chronic inflammation,” he said.

    And in fact, chronic inflammation, as a result of too many sugary treats, can lead to an increase in wrinkles and looser skin as we all get older. Dr Carl revealed:, “Chronic inflammation in the skin also includes a pathway that causes degradation of collagen and elastin, which results in signs of skin ageing such as lack of firmness, lines and wrinkles. Diets low in sugar are advisable to anyone who wants to improve the condition of their skin.”

    Tammy Richards recommends adopting a Mediterranean diet as much as you can, with plenty of healthy fats and complex carbohydrates. She revealed: “These (complex carbohydrates) transition to glucose at a lesser rate than refined sugars and therefore do not cause a spike in insulin. And healthy fats work as an anti-inflammatory and will therefore aid in combating breakouts.”

    What are the main different types of sugar?

    Natural sugars

    Alamy Stock Photo

    If you’re keen to cut down on the amount of sugar in your diet, you’ll need to understand a little bit about the different types – plus, how to recognise them on food labels. Because, although we refer to sugar with a blanket term, there are actually lots of different iterations of the ingredient, coming in slightly varying forms depending on where it is found. These include:


    This is the white crystal-type of sugar we have in our cupboards, and is probably the first one that pops into most of our heads. This is the one most commonly found in cakes, biscuits, pastries, and other processed products.

    Lactose, fructose and maltose

    There are another three main types of sugar, with George revealing that lactose is the sugar naturally found in milk and milk products, while fructose is the sugar you would naturally find in fruit and honey. Finally, there’s maltose, the sugar naturally found in barley.


    Glucose isn’t something found in foods – it’s called blood sugar, and when we eat carbohydrates, our bodies breakdown 100% of that into glucose. George Hamlyn-Williams, principal dietitian at the Hospital Group, explained: “Glucose is found in our bloodstream. Other forms of sugar (sucrose, lactose etc) break down into glucose after we eat them; the glucose is then absorbed into the blood.” If your blood sugar often drops too low – if, for example, you are diabetic – you can take glucose tablets to return it to normal.

    Common names for sugar on food labels

    In the book How to Feel Differently About Food by Sally Baker and Liz Hogon, it’s stated there are more than 50 different names for sugar – although today it’s widely believed to be closer to 60. So, vigilant with checking labels, if you want to avoid the sweet stuff.

    Sally explained, “Sugar comes disguised under many different names and the food scientists are adding more all the time. We live in the age of sugar, with a myriad of sugar derivatives and substitutes found everywhere in modern processed foods.

    “When you start reading food labels you realise that sugars, hidden in plain sight, can be found almost everywhere, often in the least expected foods, from bread to soups to sauces. The only foolproof way of avoiding them is to diligently read labels and be vigilant with regard to what you choose to buy.

    Sally recommends being  aware that any ingredient ending in ‘ose’ is a sugar. The most common names for hidden sugars in food include:

    • Beet sugar
    • Cane sugar
    • Caramel
    • Agave nectar
    • Muscovado sugar
    • Corn syrup (or high fructose corn syrup)
    • Rice syrup
    • Molasses
    • Golden syrup
    • Evaporated cane juice

    How much sugar is in our favourite foods and drinks?

    Credit: Getty Images

    How much sugar in a can of Coke?

    Without caffeine, there’s thought to be around 25g of sugar in a 330 ml can of coke, given that there is roughly 10g of sugar in coke per every 100 ml. That’s a huge amount!

    How much sugar is there in energy drinks?

    While an average can of Red Blue contains seven teaspoons of sugar, some varieties contain much, much more. Drinks a can of Rockstar Xdurance and you’ll be consuming 17 teaspoons

    How much sugar is in ketchup?

    The British Heart Foundation says that there is a teaspoon of sugar in one tablespoon of ketchup – so be careful how much you’re putting on your plate next meal time!

    How much sugar is in a banana?

    It might shock you, but in the average 100g banana, there is thought to be around 12g of sugar, which is around 3 teaspoons. However, it’s important to remember that this isn’t added sugar, but natural, and as such, it can help control blood sugar levels, while the natural fibre in a banana is always good for our diets.

    How much sugar is in a doughnut?

    This one might not be so surprising, with the British Heart Foundation estimating that there are around 3.5 teaspoons of sugar in a 71g jam doughnut.

    How much sugar in an apple?

    It’s estimated that there are around 10g of sugar in an apple – adding up to about two teaspoons. However, most of that sugar is naturally- occurring fructose, meaning it’s not anywhere near as bad for you as a doughnut!

    How much sugar in a Creme Egg?

    As you might expect, this one is a whopper. It’s thought that there’s around 26 grams of sugar in one single creme egg, which is equal to around six teaspoons – eek! Earlier this year, we  reported how one mum was so shocked after discovering the amount, she illustrated it with this photo:

    Sugar and cancer: is there a link?

    Recently, scientists and health experts have also been exploring the link between sugar and some types of cancer. So far, there’s not been a whole lot of conclusive evidence to suggest that sugar causes cancer, but there does seem to be some relation between the two. Tumorous cells consume huge amounts of glucose (sugar) to fuel their growth, and so it’s easy to assume that an abundance of them can potentially, help to fuel the cancer.

    Plus, Cancer Research UK have pointed out that eating too much sugar can cause you to become overweight, and being overweight “can cause up to 10 types of cancer, including two of the most common – breast and bowel cancer – and two of the hardest to treat – pancreatic and oesophageal cancer.”

    But don’t panic – because so far, there’s been no solid proof that sugar causes cancer. In fact, Cancer Research UK says, “there is no good evidence that eating sugary foods directly causes cancer or makes it worse.”