Barbacoa Al Mojo De Ajo

PERSPECTIVES
OPINION

Obesity and the brain: how
convincing is the addiction model?
Hisham Ziauddeen, I. Sadaf Farooqi and Paul C. Fletcher

Abstract | An increasingly influential perspective conceptualizes both obesity and
overeating as a food addiction accompanied by corresponding brain changes.
Because there are far-reaching implications for clinical practice and social policy if itbecomes widely accepted, a critical evaluation of this model is important. We
examine the current evidence for the link between addiction and obesity, identifying
several fundamental shortcomings in the model, as well as weaknesses and
inconsistencies in the empirical support for it from human neuroscientific research.
Obesity, which has a profound impact on
personal well-being and on thedemand for
health care, is at pandemic levels1. Central
to weight gain is the development of an
energy imbalance, a situation that arises as
a result of complex interactions between an
individual’s biology and environmental factors1,2. Clinicians, researchers and politicians
recognize the importance of understanding
how the brain interacts with an obesogenic
environment and the correspondingpotential for neuroscience to develop our understanding of the causes and consequences of
obesity. The messages now emerging from
the neuroscientific research community may
therefore have an unprecedented impact on
policy development.
A fast-growing consensus is that obesity
might be understood within the same
neurobiological framework as addiction and
that research, investigations,treatments
and policy should be shaped accordingly 3.
Essentially, the view is that obesity results
from an addiction to food that strongly
resembles addiction to drugs, both behaviourally and in terms of underlying neural
processes. This idea is exerting a tremendous
influence on the field of obesity research and
has driven cogent, although unsuccessful,
arguments for the inclusion of obesityor
overeating as a category in the fifth edition
of the Diagnostic and Statistical Manual of
Mental Disorders (DSM-V)4,5. Although
there has been debate about the validity of

arguments for phenotypic similarity between
overeating and addiction — and questions
over whether such a model can generate realistic goals for policymakers3 — one area that
has not yet been critically scrutinized isthe
human neuroscience work that is often cited
in support of the addiction model and that
provides a pervasive framework for design
and inference in human studies of overeating.
In this Perspective article, we describe
how the addiction model has been applied
to obesity and overeating and critically
review each of the five main lines of research
that are usually invoked to support thisconflation. At the outset, it is important to
acknowledge that the food-addiction literature has largely adopted the clinical model
of addiction as defined by the DSM-IV.
Although this model has clinical validity, in
the addiction research literature it has been
supplemented, and to an extent superseded,
by powerful neurobiological models that
have decomposed the clinical syndrome interms of its core cognitive processes and
their possible neural substrates (BOX 1).
This approach, which is based on a growing
understanding of the neurobiology of
addiction, is welcome and — as we discuss
— may offer new ways of identifying overlap
between obesity and addiction. However,
this article is primarily concerned with the
existing arguments in favour of addiction as
a model forobesity, arguments that draw on
clinical definitions.

NATURE REVIEWS | N EUROSCIENCE

Obesity and addiction: two views
The addiction model has been applied
to obesity in a number of ways. Central to
each is the idea that someone can become
a ‘food addict’. What might this mean? Two
broad ideas have been discussed. The first
is that certain foods (those high in fat, salt
and sugar 6–8)...