How Hidden Sugar Is Ruining Your Diet

How Hidden Sugar Is Ruining Your Diet
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The World Health Organization (WHO) recently released draft revised guidelines on daily sugar intake for adults and children. But if people are to follow the WHO’s advice, they need to start thinking about all the hidden sugar in their diet.

Juice picture from Shutterstock

The draft guidelines are based on two reviews of research examining the links between consumption of sugars and health, specifically weight gain, and tooth decay. When finalised, they will provide recommendations aiming to reduce health problems associated with excessive sugar intake.

Current guidelines, published in 2003, recommend sugars provide less than 10 per cent of total daily energy intake (that’s your kilojoule intake from one day). The new draft guidelines maintain that recommendation, but suggest a reduction to below 5 per cent would carry additional health benefits.

An average adult within the healthy weight range has a total energy intake of about 8700 kilojoules per day. For this person, 10 per cent of energy intake equates to approximately 50 grams (around 12 teaspoons) of sugar per day, while 5 per cent is about 25 grams (around six teaspoons) of sugar.

Hidden sugars

The suggested limits apply to sugars added to food by manufacturers, cooks or the consumer of the food, as well as sugars naturally present in honey, syrups, fruit juices and fruit concentrates.

The problem is that sugars in these latter (and many other) foods are “hidden” in the sense that people don’t always account for them when considering their sugar intake.

And there’s increasing concern that these kinds of sugar sources may displace more nutritious foods in the diet, thereby increasing the risk of ill health through conditions such as diabetes and heart disease.

Sugars also play a major role in the development of dental caries or cavities (tooth decay), which continues to cause pain and loss of function in many people.

There are masses of hidden sugars in other common foods too. Most of the processed foods available in supermarkets today, for instance, contain added sugar — often in surprising quantities. This includes even those that don’t taste particularly sweet. Tomato sauce, for instance, is considered a savoury food, but one tablespoon contains approximately four grams (about one teaspoon) of sugar.

Watching your intake

High-sugar foods and drinks that provide little nutritional value are the ones to watch out for — these are mostly discretionary or junk foods (also known as “extras” or “sometimes foods”), such as sugary drinks, lollies, chocolate, biscuits, and cakes.

The Australian Dietary Guidelines point out that discretionary foods are not a necessary part of the diet — and there are good reasons why. The image below illustrates how much sugar is provided by one serve of some of these foods (recall that for an average healthy adult, 25 grams of sugar is 5% of daily dietary intake).

It’s clear that adding just one serve of some of these foods (and others like them not described above) to an otherwise sugar-free diet means exceeding the WHO draft suggested limit of 5 per cent. In some cases, it would even mean approaching the recommended upper limit of 10 per cent!

What’s more, these serving sizes may not accurately reflect what most people eat. People don’t tend to use standard serving sizes and may eat even more than the quantity of sugar shown above.

Worth the struggle

Sugar is also commonly added to grain foods, especially breakfast cereals and bread. A standard 30-gram serve (two-thirds of a cup) of typical sugar-sweetened breakfast cereal, for instance, contains approximately eight grams of sugar. And a 40-gram slice of commercial white bread contains approximately one and a half grams.

But unlike most discretionary foods, bread and breakfast cereal usually also provide valuable nutrients. Still, because they provide more essential nutrients, it’s better to choose mostly wholegrain or high-fibre (or both) cereals and bread, without added sugar.

Sugar has a place in a healthy diet, especially for encouraging consumption of nutritious foods by fussy eaters. Adding a teaspoon of honey to rolled oats to make breakfast more palatable, for instance, is better than not eating oats at all. Neither the Australian Dietary Guidelines nor the draft WHO guidelines recommend avoiding sugar entirely.

Although it may be difficult to meet such guidelines, they help raise awareness about the importance of a balanced diet, including the need to limit sugar intake. Don’t beat yourself up for exceeding the daily limit occasionally (or falling short for some other nutrient), but remember that it’s definitely worth the struggle to try to match the recommendations.

Kate Flinders is Defence Scientist (Nutrition) at Defence Science and Technology Organisation. Chris Forbes-Ewan is Senior Nutritionist at Defence Science and Technology Organisation. Kate Flinders is a member of the Dietitians Association of Australia (DAA) and as a member of this association she is accredited as an Accredited Practising Dietitan (APD) and Accredited Nutritionist (AN). Chris Forbes-Ewan had previously received funding from the NHMRC for revising the Australian Dietary Guidelines.

The ConversationThis article was originally published on The Conversation. Read the original article.


  • Nice article, the more information available on this the better. The initial issue was that people were worried that there was too much fat in their diets, so they removed the fat and added sugar. Turns out Suger makes you fatter faster than animal fat… go figure. Some of the latest information out now, suggests that fat isn’t that big a problem, certainly not for the heart. So lets put a little bit of fat back in, and reduce the sugar a lot…!

  • I’m surprised that fruit juices only get a passing mention. Except for a few added vitamins, the nutritional content of fruit juice is a close match for the same quantity of soft drink.

    It’s not inaccurate to think of fruit juice as sugar water with some impurities. You’re probably better off having a Coke and a vitamin pill than drinking the same quantity of orange juice.

    That doesn’t mean you should start quaffing Coke. It just means you should be aware of what you are drinking – you’re probably better off sticking to water and eating some actual fruit, rather than drinking something that has had the best parts removed.

    • Well fruit juices contain protein,fat and fiber as well as vitamins and less sugar than fizzy drinks,also it is fructose which is better than refined sugar, soft drinks are just empty calories.

      • This is not accurate. Your body only identifies 2 types of sugar, fructose and glucose. “Refined sugar” or table sugar is sucrose (made up of glucose and fructose). Each type of sugar is processed separately and used for different functions in the body. In high quantities, fructose is worse for you because it goes straight to your liver, where glucose enters your blood (affecting your blood sugar)..

        Fizzy drinks often contain fructose as a sweetener (high-fructose corn syrup) and, as such, have the same effect as fruit juice.

      • It’s been a while since this was posted, but generally no, fruit juices do not contain these things, or at least not enough to be nutritionally relevant.

        If we want to believe the figures in Wikipedia, 100g of apple juice includes 0.1g of protein and 0.2g of dietary fibre, 0g of fat – and 11g of sugars. That amount of fibre and protein is not enough to matter; we’re talking 0.1 and 0.2% of the total volume.

        Now a smoothie (a piece of fruit stuck in a blender with as little as possible other stuff added) is another thing, but most juices sold have had the pulp (the best part!) removed.

        Fructose isn’t better than refined sugar; in several ways it’s worse. Fructose has been linked to metabolic syndrome; it follows a different metabolic pathway to glucose (via the liver) and is more likely to be converted into fat. Sucrose is half fructose and half glucose, basically, so has some of the same effect but at a lesser magnitude.

        All that said – you’re probably best off drinking water, or perhaps a diet soft drink.

    • I thought it was being dealt with implicitly. Sugar (sucrose) breaks down to equal parts glucose and fructose as part of the digestive process.

      • See my comment above about glucose and fructose being broken down differently by your body.

        Only glucose affects your blood sugar, while large quantities of fructose will go straight to your liver..

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