Thursday, 21 April 2011

Watching the waistline figures

'Food, glorious food' went the lyrics to the song from the musical Oliver!

Nowadays however, we are bombarded with messages that food might not be all that glorious, certainly not the types and amount of food that we, in the developed world, are all consuming in these modern times of plenty.

Being overweight or obese is a real issue nowadays. If you have the time, have a look at the figures being produced by the US CDC on prevalence rates over the past 20 years or so. It's the same message and same message here in the UK. Plenty = problems.

In amongst all this data, some reports have indicated that there might also be certain groups of people at increased risk of being overweight and obese; one of them being those diagnosed with learning and/or developmental disabilities where diet, feeding and exercise patterns may already be problematic. Yet another potential co-morbidity to look out for.

I could cite various papers to demonstrate this finding in learning disability but I will cite this one from 2008 simply because it has quite a big study group and controlled for lots of different factors. Their findings: well, obesity was running at about 20% of their subject group (based in the UK) which is actually about the same as for the rest of the UK population at a similar time. The authors do suggest that this figure might be an underestimation but I can't find anything substantially wrong with their methodology aside from the fact that 'intellectual disability' covers a lot of ground in terms of people and symptoms.

Overweight and obesity have also been looked at with reference to autism spectrum conditions and the question asked whether autism may be associated with increased risk of obesity. The contemporary figures where data is available are: USA - 2010 (30%) & USA - 2010 (23%), China - 2010 (31%). Going back a few years the figures are slightly different: USA - 2005 (19%), UK - 2004 (10%) (yes, this last one is mine). Plotting these figures onto the total population obesity figures and we get roughly the same sort of trend appearing in terms of overall prevalence and direction.

So to the question of whether there is an increased risk of obesity in autism. Mmm, the data appears to be saying that there is no doubt obesity is associated with autism, but nothing at the moment to say that levels are anything substantially different from that observed in the general population. A case of 'sauce for the goose'?

There are some obvious questions to ask about the data and the conclusions reached in this relatively brief post. Is the data collected the same way - objective measurements of height and weight, same criteria across all data collection? Are we comparing alike age-groups? Are we taking into account things like side-effects of medication, activity levels, feeding habits and patterns, etc?

And you would of course be right to ask such questions because I don't have all the answers - I am, once again, just questioning them.