While genes can play a part in diabetes, the unhealthy diet and lack of exercise in our modern era are claiming diabetic victims too.
In both developed and developing societies, a clear link has been observed between obesity rates and the sharply rising number of people falling prey to type-2 diabetes.
Although both type-1 and type-2 diabetes may have hereditary aspects, obesity, lack of exercise and unhealthy diets can greatly increase the risk of the latter's onset.
In type-1 diabetics, patients' bodies produce little or no insulin. Thus, they are dependent on daily insulin injections to control their blood-glucose levels.
Those with type-2 diabetes do not usually require insulin injections but can work on controlling their blood-sugar levels by watching their diet, exercising or taking certain oral medications.
Through healthy eating habits and increased physical activity, the onset of type-2 diabetes can be prevented in up to 80 per cent of cases, data from the International Diabetes Federation (IDF) suggests.
In Singapore, doctors who spoke to Mind Your Body said more youths are at risk of type-2 diabetes now, compared to a few decades ago.
Associate Professor Lee Yung Seng, a consultant with the University Children's Medical Institute at the National University Hospital (NUH), said almost half of the newly diagnosed adolescent diabetes patients he sees have the type-2 variety.
He added: 'A lot of them are overweight and discovered through opportunistic screening.'
Early stage type-2 diabetes often shows few or no symptoms.
Prof Lee explained that especially in the case of young type-2 diabetics, a sedentary lifestyle, poor eating habits and excessive weight gain are very strong contributing factors.
Even in the case of type-1 diabetes in children and adolescents, while the actual factors are still uncertain, those who are overweight or lead unhealthy lifestyles may fall victim to it at an earlier age.
Dr Fabian Yap, head of endocrine services at the KK Women's and Children's Hospital (KKH), said that compared to the early 1990s when there were hardly any cases of children and adolescents with type-2 diabetes, about one-third of new cases he sees now are type-2.
He said KKH, which attends to around 65 to 70 per cent of Singapore's child and adolescent diabetics, has seen about 50 new cases of diabetes annually over the last 10 years.
Dr Yap estimated that 55 per cent of diabetics diagnosed at age 12 were found to have type-2 diabetes. Twelve is the most common age at which this form of diabetes is diagnosed in young patients, he said.
'This tells you that at this age, it is important for doctors to diagnose what type of diabetes a patient has,' he said, adding that hormonal changes during puberty tend to 'unmask' latent diabetes.
He also noted that 80 to 90 per cent of the young type-2 patients he sees are overweight.
Both doctors agreed that in dealing with diabetic children and teenagers, controlling the condition is key but many face trouble in complying with the treatments.
'Teenagers, especially, undergo a lot of changes physically, emotionally and in their social circles. They tend to seek more independence and may develop priorities in life other than their diabetes,' Prof Lee said.
This could lead them to risk-taking behaviour like skipping insulin injections and medications, as well as forgoing dietary control.
Dr Yap said the successful self-management of diabetes in a young patient ultimately depends on the person's maturity.
'There are some who understand their condition and can start injecting themselves at age eight. On the other hand, there are 16-year-olds who can't do anything on their own,' he noted.
Both doctors agreed that family support is crucial to proper diabetes management in younger patients.
Such support can be shown through exercising together and changing the whole family's diet to encourage better eating habits.
Mismanagement of young diabetics' conditions can lead to eye and kidney problems, along with increased risk of heart attacks and stroke later in life, they said.
One young patient learning to manage his condition is 14-year-old Iskandar Aziz, who was diagnosed with type-2 diabetes in March last year.
He was hospitalised after an asthma attack but a check found his blood-sugar levels to be high.
Iskandar's mother, Ms Salmiah Razat, 40, was surprised her son has diabetes. She had thought that her son's obesity related only to breathing problems.
Since then, Ms Salmiah has made a concerted effort to get her entire family to adopt a healthier diet.
'As a family, we now take walks in the park. We've also changed our diet in support of Iskandar,' she added.
Iskandar, who is 1.6m tall and used to weigh about 100kg, has started swimming and running regularly, along with hitting the gym once a week.
Thanks to his new lifestyle, he has lost about 5 to 6kg in the last year.
He is grateful he has a supportive family and friends who constantly remind him to watch his diet and not to eat too many sweets.
It has been a learning experience for Ms Salmiah too. She said it was important to avoid 'negative thinking' when teaching a young person to manage his diabetes.
She added: 'We try to maintain a positive attitude in encouraging Iskandar to change his lifestyle. Still, it takes some time for him especially when it comes to changing eating habits.'
This article was first published in Mind Your Body, The Straits Times on Nov 13, 2008.