Madam, - Congratulations to your Medical Correspondent, Dr Muiris Houston, for his informative series "Your Health". The report on childhood obesity was both startling and timely in alerting parents to the increased prevalence of this disease and to the associated complications and health risks.

As Dr Houston points out, the syndrome is complex: social, psychological, endocrinological and metabolic factors are all involved. The extent to which a lack of physical activity contributes to this condition is particularly difficult to determine. Some studies examining the relationship between exercise and obesity have been conducted after the subjects have become obese, and therefore cannot assess whether under-activity helped to cause the obesity or simply reflects less activity induced by more weight.

Measuring activity is also problematic: because body mass is a primary determinant of energy expenditure, an obese adolescent, with apparently low physical activity can be expending more energy than a leaner, more active peer. Nevertheless, several studies have indicated that inactivity seems to be a key factor in predisposing to obesity.

Perhaps parents could play a more positive role in children's lifestyle choices. Dr Houston refers to the study published in the March issue of the Irish Medical Journal which found that fewer than a third of children in the higher socio-economic groups walk to school. Are some parents simply acceding to their children's requests to be driven to school when walking is a realistic option?

Also, significant gender differences were observed, with girls being about 21 per cent less active than boys, and there was a significant decline in girls' activity after the age of 11 or 12. An accelerated decline in girls' activity has hitherto been observed only in the teenage years. Girls were also observed to have lower physical self-perception than boys.

Gender differences in children's activity are not as marked in other European populations, such as in Scandinavia, where due importance is attached to physical education at all stages of young people's education, from primary to third level.

If the gender gap in activity is to be narrowed, girls clearly need more encouragement to be active, more competence in motor skill, and positive reinforcement of all dimensions of the physical self.

The introduction of the new Primary PE curriculum for all Irish national primary schools will begin in September 2003. This is designed to equip children with the appropriate motor skills to participate in a wider range of physical activities, and to benefit from the associated enjoyment and heightened self-image.

Adequate resources must be directed to implement this programme fully. It could be the catalyst needed to change the increasingly sedentary lifestyles of many young people. - Yours, etc.,


Assistant Dean Academic,

College of Education,

University of Limerick.