Worldwide, the percentage of the population with obesity and diabetes has grown steadily in recent decades, and Singapore is no exception ("Rising obesity among young set to worsen diabetes rate"; Feb 22).

Too much body fat can increase our risk of hypertension, diabetes and heart disease.

How then can we keep our body weight in check and stay healthy?

Online awareness campaigns from the Health Promotion Board are currently drawing attention to the sugar and calories in beverages, including juices.

This raises the question of whether juices are as unhealthy as sugar-sweetened beverages such as soft drinks.

Clearly, soft drinks, packaged ice teas, "fruit drinks" and sports drinks are generally high in sugar and calories. A 250ml glass of a typical soft drink or blackcurrant "fruit drink" contains more than six teaspoons of sugar and requires the equivalent of a 15-minute brisk walk to burn off the calories.

Beverages can be quickly consumed and digested and can lead to less satiety than the same amount of calories from solid foods.

Indeed, the consumption of sugar-sweetened beverages can lead to excess weight gain.

Even one glass a day is linked to an 18 per cent higher risk of Type 2 diabetes, according to a recent study published in the British Medical Journal.

But how about 100 per cent fruit juice without added sugar?

A single glass of commercial apple juice or sugar cane juice provides six teaspoons of sugar, and orange juice provides five teaspoons of sugar, which is similar to sugar-sweetened beverages.

Home-squeezed orange juice is slightly better, providing 41/2 teaspoons of sugar per glass.

When fruit is juiced, most of the pulp is lost, resulting in a loss of fibre and healthy plant compounds such as flavonoids, while sugar remains in the juice.

A medium orange contains 3.6g of fibre while fresh orange juice contains only 0.5g of fibre.

In the British Medical Journal study, consuming a glass of fruit juice a day was linked to a 7 per cent higher risk of Type 2 diabetes.

Some fruit juices are certainly more nutritious than soft drinks, particularly if they are freshly squeezed, and the impact on diabetes risk is likely to be smaller than for soft drinks.

Still, consuming fruit juices on a daily basis adds substantially to sugar intake.

The bottom line is that if you are frequently consuming high-sugar beverages, including fruit juice, cutting this out of your daily routine is an effective step to reducing your sugar intake and can help to keep your body weight in check.

Rob M. van Dam (Associate Professor)