21 October 2016
Beverages such as sodas are notorious for high levels of free sugar. Photo: Reuters
Beverages such as sodas are notorious for high levels of free sugar. Photo: Reuters

Why it’s important to understand sugar better

During hot summer days, people tend to consume a lot of sodas and other cold drinks to quench their thirst. What everyone seems to forget is that most beverages contain high levels of sugar, which can be detrimental to human health.  

From the perspective of nutritional science, all sugars are simple carbohydrates. Any one gram of intake would produce about 4 kilocalories which is converted into glucose in the bloodstream.

There’s close link between sugar intake and health problems such as obesity and tooth decay. One straightforward way of dealing with it would be to just curb your sugar intake.

Nevertheless, given its usefulness in terms of enhancing the food flavor, moisture and texture, as well as the fact that some ingredients themselves are just sweet in nature, we should first understand more about sugars and reduce the intake of some particular types.

Food such as fruit, milk and honey is sweet by nature, and so the sugar it contains is defined as intrinsic sugar. Meanwhile, any sugar — be it white refined sugar, raw unrefined brown sugar, or syrup — that is added during food processing is classified as extrinsic or added sugar.

For instance, the “no added sugar” label printed on a jam jar doesn’t mean that the jelly is sugar-free. It only implies that it is something slightly better as no extra extrinsic sugar is added to the already sweet product.

And there is a new concept of “free sugar”, and this is the type we have to reduce consumption throughout life.

According to the World Health Organization (WHO), it refers to monosaccharides (such as glucose, fructose) and disaccharides (such as sucrose or table sugar) added to foods and drinks by the manufacturer, cook or consumer, and sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates.

The current WHO guideline recommends adults and children reduce their daily intake of free sugars to less than 10 percent of their total energy intake, or no more than 50 gram of free sugars (200 kcal) in a 2,000 kcal diet of an adult, and no more than 30 to 40g for children.

A further reduction to below 5 percent or roughly 25 grams (6 teaspoons) per day would provide additional health benefits.

The recommendations are based on analysis of the latest scientific evidence. It shows, first, that adults who consume less sugar have lower body weight and, second, that increasing the amount of sugars in the diet is associated with a weight increase.

In addition, research shows that children with the highest intakes of sugar-sweetened drinks are more likely to be overweight or obese than children with a low intake of such drinks.

It is further supported by evidence showing higher rates of dental caries (commonly referred to as tooth decay) when the intake of free sugars is above 10 percent of total energy intake compared with an intake of free sugars below 10 percent of total energy intake.

However, the existing food labeling only gives consumers a lump-sum figure of carbohydrates without specifying which is which.

Consumers should also read the list of the ingredients. Free sugars could be under the aliases such as sucrose, white refined sugar, rock sugar, glucose, fructose, high-fructose corn syrup (HFCS), high maltose corn syrup, maltose, honey, etc. If they appear at the front of the queue, it also means they are the major components in terms of weight.

Apart from the notorious beverages, most bakery products like bread, biscuits, cakes contain high level of free sugars. Judging by taste is unreliable, as savory snacks like pork floss and rice cakes are also good sources of free sugars.

There are people who argue that fructose, honey and raw unrefined sugars are healthy sugars. It is relatively true only when they are compared to glucose, in which they require a long time for digestion and absorption.

Anyway, they are sugars, and like many others, would contribute energy and glucose to the body. And according to the abovementioned definition, sugars naturally present in honey, syrups, fruit juices and fruit juice concentrates are considered free sugars and the intake should be reduced.

Speaking of artificial sweeteners, though they are not monosaccharides or disaccharides — which means they are not releasing energy or increasing blood sugar as much as the real sugar — they still provide a sweet taste. Addiction to this sensation is not a desirable habit.

Growing out of the dependency on the taste should be set as the ultimate goal.

This article appeared in the Hong Kong Economic Journal on June 7.

Translation by Darlie Yiu

[Chinese version 中文版]

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