Sugar’s impact on your body: 9 hidden side effects

Updated January 2024 | 5 min read
Expert contributor Deepti Khatri, senior health coach and clinical performance lead, HCF
Updated by Beth Wallace

Rising levels of obesity and type 2 diabetes are highlighting concerns about sugar’s impact on your body. Discover the impact of consuming too much sugar and how to curb your sweet tooth.

Sugar is a simple carbohydrate that the body converts into glucose and uses for energy. There are naturally occurring sugars in fruit and dairy products, and sugars that are added to food and drinks. But how much of the sweet stuff are we really consuming and what are the impacts of too much sugar on our health?

For both adults and children, the World Health Organization (WHO) recommends that ‘free’ sugars – sugars added to food and drink, as well as those naturally present in honey, syrups and fruit juices – should make up no more than 10% of your daily kilojoule intake. For an adult with a healthy body mass index (BMI), this works out to about 12 teaspoons (50 grams) per day. For greater health benefits, the WHO suggests reducing sugar intake even further, to less than 5% of your total energy intake, or around 6 teaspoons (25 grams) per day.

However, University of Sydney research suggests 55% of Australians are exceeding the WHO’s recommended daily intake and our love of sweet treats is largely to blame. Researchers found sugar-sweetened beverages were the greatest source of added sugar in the Australian diet, followed by sugar and sweet spreads, and then cakes, biscuits, pastries and batter-based products.

Dietitian Deepti Khatri, HCF's senior health coach and clinical performance lead, warns the health impacts of too much sugar can be wide ranging, but there are plenty of ways to cut excess consumption while still satisfying your sweet tooth.

1. A high-sugar diet can make your organs fat
   Consuming too much sugar and fructose (a common sugar-like food additive) triggers your liver to store fat, which can lead to non-alcoholic fatty liver disease – a condition rarely seen prior to 1980.
   
   What you can do: Deepti recommends checking the nutrition information panel on foods and opting for those with the least sugar content, keeping in mind that it might be labelled as honey, maple syrup, golden syrup, agave syrup, rice malt, dextrose, glucose, sucrose, maltose, maltodextrin, molasses or coconut sugar. "The amount of sugar per 100g is an easy way to compare products for their sugar content," she says. "For example, if one cereal has 15g of sugar per 100g and another has 5g of sugar per 100g, the second option may be the better one."
   
   
2. Too much sugar can increase your risk of developing diabetes
   Though sugar doesn’t directly cause type 2 diabetes, eating too much of it can lead to weight gain, which is a risk factor for the disease, says Deepti. "The risk of diabetes may be reduced by limiting added sugar, which helps to improve glucose tolerance," she adds.
   
   What you can do: Aim to maintain a healthy weight by eating whole foods such as fruit, vegetables, nuts and whole grains. For support with weight management, eligible HCF members can kick start their journey to better health with the CSIRO Total Wellbeing Diet. To support diabetes management, eligible members with the right cover can also access benefits, like claiming back on blood glucose monitors and insulin pumps.
   
   
3. It can lead to heart disease
   Chronically high insulin levels cause the muscle cells around each blood vessel in your arteries to grow faster than normal, leading to high blood pressure.
   
   What you can do: Try to count the grams of sugar you’re consuming and try not to exceed the WHO’s recommended daily intake. Though there are different types of sugar – raw sugar vs white sugar vs brown sugar, for example – Deepti says it’s important to remember that, from a kilojoule perspective, they’re identical. "The only real difference between raw sugar and white sugar is that raw sugar contains molasses and small amounts of minerals, whereas white sugar undergoes processing so that the molasses is removed, and it doesn't contain any minerals," she says. Eligible HCF members can access a free heart health check at certain times of the year, which includes a blood sugar and total cholesterol reading as well as a blood pressure check.
   
   
4. Excess sugar can play havoc with cholesterol levels
   Studies have found that people who consume high levels of added sugars record the biggest spike in unhealthy cholesterol levels, and the lowest healthy cholesterol levels.
   
   What you can do: Eating protein-rich eggs for breakfast helps combat sugar cravings. Deepti also advises against adding sugar to tea or coffee, or at least reducing how much you add over time. "Limit discretionary or ‘junk’ foods like lollies, chocolates, cakes, pies, pastries and biscuits," she adds. "And limit sugary drinks such as soft drink, flavoured milk and fruit juice – choose water or light milk instead."
   
   
5. It’s linked to Alzheimer’s disease
   Research linking insulin resistance and high fat diets to Alzheimer’s portrays the condition as a metabolic disease where the brain’s ability to process glucose is damaged.
   
   What you can do: Avoid sweet, fatty foods. Here’s a list of 57 sneaky names for sugar you may not be aware of.
   
   
6. Eating too much sugar can turn you into an addict
   Sugar activates the brain’s reward system. When we eat sweet things, our dopamine levels surge, signalling that the event was positive and therefore reinforcing the behaviour. It doesn’t take long to acquire a tolerance, meaning you need larger doses.
   
   What you can do: Cut down on the sweet stuff and allow at least a week for your tastebuds to adjust. To get over the hump, try eating smaller meals more often and, if you can’t fight the craving, opt for a sweet treat of no more than 625 kilojoules (about 150 calories). Deepti also suggests finding alternative ways to add flavour to food and drinks – with fruit or spices like cardamom, cinnamon or nutmeg serving as healthy sugar substitutes. "Add banana or berries to your breakfast cereal, muesli or porridge to naturally sweeten your breakfast," she says.
   
   
7. It disables your appetite control
   Fructose acts negatively on the leptin hormones that tell your brain when you have eaten enough. A high-fructose diet can leave you feeling hungry, even when you’re overeating.
   
   What you can do: Walk it off. Studies have shown that even brief periods of exercise, like a brisk 15-minute walk, can help reduce sugar cravings.
   
   
8. It influences your food choices
   If you consume a high volume of sweet foods, you’re likely to want more sweet foods, creating a snowball effect that potentially leads to weight gain.
   
   What you can do: Aim to cut back on ‘free’ sugars, but remember that foods containing naturally occurring sugars, such as fruit, also contain dietary fibre, vitamins, minerals and antioxidants, and should be included as part of a healthy, balanced diet.
   
   
9. It's associated with a higher risk of depression
   Apart from the fact it takes just 30 minutes to go from a sugar rush to a crash, research reveals that consuming large amounts of ultra-processed food is associated with a higher risk of depression.
   
   What you can do: Take an honest look at your diet, figure out exactly how much sugar you’re consuming and aim to make healthier choices.

Personalised support for diabetes and heart conditions

You can trust HCF to help you be your healthiest self, that's why we’ve launched The COACH Program®. Delivered by qualified health professionals, this telephone support program is provided by health coaches, at no extra cost for eligible members^{^} with heart conditions or diabetes.