When it comes to food, there is one universal truth: we all have an inbuilt preference for sweet tastes. And it seemingly starts from birth, as newborns will happily drink more fluid when it’s sweetened with sugar.
Young children certainly prefer intense sweet flavours; a recent study found their preferred sucrose concentration was 11 teaspoons of sugar in a 240ml glass of water – double the sugar level of a soft drink. Thankfully, as we age, our preference for sweetness declines; this probably explains why most adults don’t add 11 teaspoons of sugar to their cup of tea. That’s a good thing, as a 2012 review of research, published in the British Medical Journal, confirmed sugar causes weight gain.
But didn’t we already know that? Well, yes and no. Dietary sugars have been linked to obesity and a higher risk of chronic disease for some time. Moreover, recent clinical trials found a high intake of sugar-sweetened drinks contributed to weight gain. However, this latest meta-analysis review, by University of Otago researchers for the World Health Organisation (WHO), combined the findings of 30 clinical trials and 38 observational studies to determine if eating free sugars affected weight. Free sugars are defined as all sugars – such as fructose, glucose and sucrose – added to foods by the manufacturer, cook or consumer, as well as sugars naturally present in honey, syrups and fruit juices.
The review confirmed that advice to reduce intake of free sugars was associated with an average 0.80kg weight reduction among people. Conversely, increased intake was associated with a 0.75kg weight gain. Although not large, the change occurred relatively rapidly when sugars were added or removed from the diet. So, although many factors may contribute to obesity, the impact of free sugars is significant enough to justify focus, the researchers concluded. WHO sugar-intake guidelines will be updated to reflect these findings.
The change in body weight linked to altered sugar intake appears to be caused by the corresponding change in energy intake; that is, if you eat less sugar, you consume less energy. So, if you replace sugar with other carbohydrates, you won’t lose weight.
Cutting added sugar from tea and coffee is a good start, but it’s also worth considering the hidden sugars that manufacturers add to processed foods. Take tomato sauce. It is 25% sugar by weight; in other words, every tablespoon of tomato sauce contains the equivalent of a teaspoon of sugar. Sugar is also found in peanut butter and other breakfast spreads, salad dressings, breakfast cereals, supposedly healthy fruit yoghurt, muesli bars and fruit juice.
Sugar is also concealed in canned vegetables and soups: beware pumpkin and tomato soups. And although fast food may be synonymous with fat, it often packs a sugar punch. KFC’s coleslaw has the equivalent of six teaspoons of sugar per cup, and oodles of sugar lurks in many pizzas as well as Thai and Indian curries.
So, enjoy an occasional sweet snack or dessert fully aware it’s high in sugar, but instead of sugar-laden peanut butter and tomato sauce, choose minimally processed foods or home-made alternatives to lower your sugar intake.
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