School uniform makers have extended their ready-made size range to handle the expanding waistlines of overweight schoolchildren.

They now stock bigger sizes - typically meant for severely overweight or obese adults.

Several manufacturers carry an extensive 12 or more sizes, up from eight to 10 sizes a decade ago.

Primary school shorts can now run from a 20-inch waistline to 42 inches, while secondary school trousers are from 24 inches to 46 inches. And it does not stop there. Some have plans to go even bigger.

Obesity rates among schoolchildren have risen in recent years, from 10 per cent in 2000 to 12 per cent in 2014.

A recent Health Promotion Board study found that if a child is overweight at age seven, he has a 70 per cent chance of growing up into an overweight or obese adult.

Why are children bigger now? Blame rising affluence and children's sedentary lifestyle.

Ten years ago, a typical Primary 1 boy would fall between sizes 20 and 24, said one uniform maker. But now, it is 22 to 26.

And where the average size for Secondary 1 students hovered around 24 inches to 28 inches in the past, it is now 26 inches to 32 inches.

To beat the flab, some schools are encouraging students to pick up a ball or racquet and play for fun during recess and after school.

All mainstream schools also offer healthier food under the Healthy Meals in Schools Programme, launched in 2011 to foster better eating habits.

One school interviewed even offers parents tips on managing their children's weight. Another has its pupils, together with their parents, set targets on their weekly physical activities and their plan to cut down on sugar intake.

But schools cannot fight the battle against obesity alone. Habits, like leading an active lifestyle, start at home. Parents must set a good example by eating right and exercising regularly. This, combined with efforts at school, will help the young to pick up good habits that will last them a lifetime.