Another product from the Framingham study! It's difficult not to be wowed by the video attached to web version of this piece - but we need to check the underlying science is sound. The basic message is that obesity is not just about you, it's about your friends and neighbours. Another reminder of why do public health - man is a social being and influenced by social processes.
Social processes are difficult to measure, which means the statistics can be incomprehensible: and incomprehensible means potentially seriously misleading.
I remember a great debate about the effects of unemployment on health which hinged on showing that cycles of unemployment matched cycles of deliberate self harm. The problem was that the statistics of matching cycles (time series analysis) is very tricky and in the end it was clear that the apparent correlation was spurious.
In this case, we have to take comfort in the fact that the analysis is published in the NEJM. It's the world's leading biomedical journal so I guess they can call on some seriously competent referees.
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