Once again, Bradford has come at the top of an unwelcome league table for levels of obesity among children in West Yorkshire.

The latest figures show that the district has the highest proportion of overweight 11-year-olds in the county, and that the level of obesity in children is above both the regional and national rates.

What is curious about these figures is that the district was actually below the regional and national averages for overweight children at reception age, when they first enter the school system.

So what goes wrong in the intervening years? It would be sensible to assume that once children start school and begin a more active programme of organised sports and exercise, their weight and general health should improve.

This is evidently not the case. Bradford Council prides itself on providing healthy school meal options, and anyone in charge of a child aged between 5 and 11 knows how much energy they generally expend over the course of a day.

It is something of a mystery, and unfortunately the finger of blame must be pointed at the snacks and meals that many of these children have at home.

If a child grows up in a home where having fatty or unhealthy food, or lots of salty snacks and sugary drinks is the norm, then they will naturally adopt those eating habits themselves.

But that is a slow - and often not so slow - route to a desperately unhealthy lifestyle and possibly even an early grave. Adults must lead by example and eat plenty of fruit, vegetables and low-fat food to pass on the message to their children.