Thursday 21 October 2021

Child obesity experiment fails spectacularly

The 'public health' lobby is keen on the 'whole systems approach' to obesity. This is not to be confused with the equally useless 'whole population approach'. The latter involves using blunt policy tools to get everybody to reduce their consumption of salt, alcohol, sugar or whatever whereas the whole systems approach has never been properly defined but involves the whole of society working to reduce obesity in some way.

The strategy of throwing any old policy into the mix in the hope that some of them will work is known euphemistically in 'public health' as the 'whole systems approach'. It is often illustrated with meaningless graphics and is anti-scientific, illiberal nonsense. Essentially, it gives activists a licence to do whatever they want regardless of the consequences.

At best, this scatter-gun approach can involve various teachers, social workers, charities and 'public health' professionals working face-to-face with people to help them have a healthy diet and control their weight. The one and only success story is Amsterdam where child obesity supposedly fell (a bit) after a whole systems approach was introduced. In practice, it's all too expensive and time-consuming for most governments and 'public health' groups to get behind, but it putatively shows that the government can do something about obesity.

The whole systems approach has now been tested in a four year randomised control trial in Australia called WHO STOPS Childhood Obesity (Whole of Systems Trial of Prevention Strategies for Childhood Obesity. Roughly 3,000 kids were treated to a wide range of 'community-based interventions'...

Some key examples of actions were (1) a rural health service changing its beverage provision and cafe to be “green only,” in line with government healthy choices guidelines; (2) a local government area constructing a new footpath to allow schoolchildren to engage in active transport more easily to and from school; (3) implementing a junior sporting-association-wide water-only policy; (4) a local primary school constructing signs encouraging children to be dropped off at set points away from the school gate to allow them to walk to school; and (5) implementing a healthy beverage policy at family day care.

So how did it go? At first, quite well.

There was a significant interaction effect between trial group and time (P = 0.006) (Table 2). Within intervention communities, the prevalence of combined overweight and obesity was 35.5% in 2015, 31.5% in 2017...

But then things started to go not so well.

...and 40.4% in 2019.


Prevalence within the control group remained stable at 34.3% in 2015 and 34.7% in 2019.

The control group started out with a slightly lower rate of overweight/obesity (34.3% vs. 35.5%) and ended the trial with a substantially lower rate (34.7% vs. 40.4%). Needless say, this was not what the researchers were hoping for, but they are keen to stress that the experiment was not a complete waste of time because...

Intake of takeaway food significantly improved in the intervention communities by 2019 relative to 2015 compared with control...


There was a significant intervention effect on water consumption (interaction, P = 0.019) with an increased percentage of girls consuming more than five glasses of water per day in intervention communities between 2015 and 2017 (18.1% increase) and 2015 to 2019 (11.8% increase) compared with control communities.

The authors do not take this to its logical conclusion and deduce that cutting down on takeaways and increasing water consumption does not lead to weight loss. Instead, they conclude that:

WHO STOPS reduced obesity prevalence over 2 years and over 4 years helped a majority of children keep their takeaway intake low... 
Childhood obesity is demonstrably preventable, and community-based interventions are effective, feasible, and acceptable to government, industry, and the public.

This is obviously not what the study shows, but in 'public health' you can say whatever you want. A more accurate conclusion would be to say that if childhood obesity rates go up despite the whole community working intensely with kids for several years, the chances of broad brush policies like advertising bans having an effect are nil.

Have I mentioned before that 'public health' is not a results-driven business?

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