Monday 24 June 2019

Did childhood obesity really fall in Leeds?

At the start of last month, there was a good news story from Leeds...
Leeds becomes first UK city to lower its childhood obesity rate 
Leeds has become the first city in the UK to report a drop in childhood obesity after introducing a programme to help parents set boundaries for their children and say no to sweets and junk food.

Only a few cities in the world, notably Amsterdam, have managed to cut child obesity. Like Amsterdam, the decline in Leeds is most marked among families living in the most deprived areas, where the problem is worst and hardest to tackle.

“The improvement in the most deprived children in Leeds is startling,” said Susan Jebb, a professor of diet and population health at Oxford University, whose team has analysed the city’s data. Over four years, obesity has dropped from 11.5% to 10.5% and the trajectory is steadily downwards. Among the more affluent families, there was also a decline from 6.8% to 6%. Overall the drop was from 9.4% to 8.8%.

Jebb seemed confident in the statistics:

“This is four years, not one rogue data point,” she said at the European Congress on Obesity in Glasgow where she presented the research, also published in the journal Paediatric Obesity.
“Everybody is going around saying Amsterdam is doing something amazing. Well, actually, Leeds is too.”
The news was covered by the BBC with a story headlined 'Has Leeds cracked the obesity problem?', and the Guardian ran an op-ed by the head of business development at the organisation that was credited with success: Henry (Health, Exercise, Nutrition for the Really Young). He said:

Since 2009, when Henry started working in Leeds, obesity rates at age five have fallen significantly (from 9.4% to 8.8%), while rates for cities with similar socio-demographic characteristics, and as a whole, have remained high.

I mentioned it on this blog at the time because it seemed promising. Alas, via ConscienHealth, I see that it has been debunked. As Eugene Milne, the director of Public Health for Newcastle, explains:

But what was missing from the news coverage and responses was the fact that there is now a fifth data point in the Fingertips data—for the period 2013/14-2017/18—and this shows the prevalence of obesity in Leeds to have risen again to 8.98%. This is because the single-year data for the city in 2017/18 showed a rise to a prevalence figure of 9.5% in the reception age group.

This true. If you look at the data, you'll see that the rate of 'obesity' among reception age children has been between 8.4% and 10.3% since 2006/07. Aside from a small spike between 2008 and 2010, there is no discernible trend. In 2017/18, the figure was 9.4%. Looking at other figures, it's not clear why anyone ever concluded that there was strong evidence of a decline.

This therefore looks like junk research in support of another cash-burning 'public health' initiative. It's another reason to be sceptical of the barrage of stories that appear in the press when the European Congress on Obesity is in town.

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