Children in Ireland should have their height, weight and body mass index (BMI) checked regularly in order to identify those at risk of becoming obese, doctors have suggested.

Currently in Ireland, one in five children between the ages of five and 18 is overweight or obese. Furthermore, between 1990 and 2008, the incidence of obesity among male teenagers rose from 1% to 8%. In female teenagers, it rose from 3% to 6%.

According to consultant endocrinologist, Dr Donal O'Shea, paediatric specialist registrar, Dr Eirin Carolan and medical student, Michael Dunne, there are a number of factors that have contributed to these trends, including diet, physical inactivity and genetics.

They pointed to a number of problems the health service has in relation to this issue, including ‘poor education regarding diagnosing childhood obesity, its associated complications and effective methods of managing and preventing it'.

The doctors explained that over the last 10 years, there have been ‘heated debates' about how to define childhood obesity. Adults are defined as obese if their BMI is 30 or above.

"However in children, BMI is not sufficiently accurate to diagnose obesity due to the differences in body composition changes occurring between genders and at different ages," they said.

As a result, children's BMIs are now mapped on a graph specific to age and gender, with cut-offs for overweight and obese based on percentiles of the population. While there are limitations to this method, it largely works.

The doctors highlighted the health dangers associated with childhood obesity, for example, it is the leading cause of paediatric hypertension (high blood pressure). Furthermore, the risk of heart disease in adulthood ‘increases incrementally with increasing BMI in childhood and adolescence'.

A number of orthopaedic complications are also associated with childhood obesity, such as flat foot, scoliosis and osteoarthritis and obesity in adolescence has been linked with a number of menstrual problems in girls, such as polycystic ovarian syndrome and amenorrhoea (the absence of periods).

"The key to preventing such complications occurring is early detection, prevention and intervention," the doctors insisted.

They noted that the ‘two main fronts from which childhood obesity should be tackled are the restriction of dietary intake and increasing physical activity'.

"While this may seem simplistic, lifestyle interventions in children and adolescents has been shown to have poor compliance rates. Education for parenting is paramount," they explained.

They pointed out that focusing only on diet, or only on exercise, does not usually lead to maintained weight loss, but ‘they are very effective in combination'.

However the doctors noted that while the child and their family need to be motivated and willing to lose weight, both parents and healthcare workers find it difficult to identify children ‘in the overweight category who are at risk of becoming obese'.

This has been shown in numerous studies worldwide, with the parents of overweight and obese children often describing them as being a healthy or normal weight.

"Regular height, weight and BMI measurements in the community or schools, as are performed in other European countries such as Finland, would be an invaluable identification tool in establishing those at risk," they said.

The doctors made their comments in Forum, the Journal of the Irish College of General Practitioners.