How did obesity become such catnip for news?

The gut microbes of the slim will, if
transferred to the obese, have a
slimming effect – or at least, they
will in mice, a twin study has
found (twin women, whose
microbes were transferred to mice.
Not twin mice.) Because mice are
habitually copraphagic (they eat
each other's shit), this amounts to
slimness being biologically
contagious. Now, all we have to do
is start eating one another's faeces,
ensuring first that we've chosen
from slim individuals, and all our
problems are over.
" Let's hope the bio-contagion is
more robust than the social
contagion," said social statistician
Vicki Bolton, in reference to a
phalanx of sociology in-jokes:
about the number of things held to
"cause" obesity, that are in fact
unprovable, or at the very least not
proven yet; and also about the
overarching problem, summarised
in this beautifully dry title by
mathematician Russell Lyons, The
Spread of Evidence-Poor Medicine
via Flawed Social-Network
Analysis. Nowhere is that spread
more visible than in the discussion
of obesity, partly because any root
cause floated by any scientist is of
immediate interest to the media,
where, by a combination of
misunderstanding and
amplification, speculation becomes
statement of fact, and suggestion
becomes proof. Well, that's the
theory anyway. It's possible that
I'm amplifying it. I'm pretty sure I
haven't misunderstood it.
Anyway, the biological contagion
does seem to be more robust than
the social contagion suggested in an
extremely controversial paper by
Nicholas Christakis and James
Fowler. So let's park the mice for
the moment.
What interests me is how obesity
became such catnip for news, such
a … I'm trying to avoid words like
"hot button issue" and
"controversy" because they really
don't do justice to the rage it
provokes. Other people's weight
became all our problem when we
started a) calling it an "epidemic"
and b) totting up how much it costs
the NHS. This is illogical.
Malnutrition costs the NHS
significantly more and yet no
moral judgment accrues around
people who are too thin or, for
reasons of incapacity, aren't being
fed properly by the people who
should be caring for them (even
though, in the second instance,
disapprobation would be both more
appropriate and more helpful than
it is in tutting at other people's
muffin tops).
Obesity has become a cipher for a
statement of political philosophy,
by people who don't want to make
a bald statement of political
philosophy. When Jamie Oliver
asks why people who have giant
TVs can't afford parsley, the
underlying point is, why should
society feel sorry for/support
people who make bad decisions?
When people like this feminist
blogger point out what food
insecurity actually means, what the
reality of poverty is in terms of
more than money, also time and
energy, her underlying point is that
there is no "individual decision"
that is separate from the collective
decisions we all make about how
society is ordered, and what our
responsibilities are to one another.
This is the essential argument of
our time, possibly of all time.
Which makes me think, imagine if
the mice and the microbes and the
faeces really do solve the obesity
problem; what will be our
battleground then?