Why do we like some foods
more than others?
What is it about burgers
and cakes that we crave?
And what is happening in our brains
when we choose what to eat?
If you hopped into an MRI machine
and were offered
a delicious chocolate milkshake,
you would see your brain’s reward
system light up like a funfair.
Right above your eyes is your
orbital frontal cortex,
a part of the brain
which is especially developed
in humans and primates.
Here, bundles of neurons respond to
different sensations and nutrients -
taste, smell, how smooth
and rich the milkshake feels -
and the more your neurons light up,
the more delicious the food seems.
Two things which particularly delight
these reward neurons
are fat and sugar.
Combinations of fat and sugar
can be even more delightful,
such as in that delicious milkshake,
or cakes, or doughnuts.
But your neurons don’t just
respond to these sensations,
they also activate when
you’re planning what to eat
in a contest with each other
to get you to choose them.
“Pick me.” says silky
smooth mouth feel.
“No! Me!” shouts sugary sweetness.
“You never pick me.” quietly mumbles
the smell of broccoli.
And once you have chosen, the
same neurons track your progress,
and as you eat, they get less and
less active as you approach fullness.
But we’re not entirely at the
mercy of the demands
of our orbital frontal cortex.
Having information about the food
can make a big difference.
Hop back into that MRI machine
and slurp down some soup.
There are two types - one is labelled
‘rich and delicious flavour’,
and the other is labelled
‘boiled vegetable water’.
Your neurons light up at the taste
of ‘rich and delicious’,
and less for
‘boiled vegetable water’.
But wait a minute.
You’ve been tricked.
Those were both the same soup.
The only difference was the name
and that was enough to completely
change your experience of it.
This experiment was also
done with wine -
telling people that
the wine cost more
made their neuron activity increase
and the wine tasted better.
Another part of the brain involved
in choosing food is the amygdala.
The amygdala also has a role to play
when you choose where to go out
with another person.
 If you’ve seen what they
prefer in the past,
your amygdala will have developed
so-called simulation neurons.
These predict the choice
you think they will make
which you can then factor into
your own suggestions
of what to eat together.
Differences in our genes are also
a factor in how susceptible we are
to the siren call
of our reward neurons,
with some people being
naturally more responsive
to the reward we feel from
eating sugar and fat than others.
Scientific experiments give us clues
about how our brains compute
our choices of what to eat,
but the way we experience these
choices in our lives and in society
is also complex.
Dr Emily Contois, Assistant Professor
of Media Studies, gives her take.
We choose the food we eat
for a lot of different reasons -
what’s available at the grocery
store? What’s convenient?
What’s affordable?
What do we have good memories about?
What tastes good to us?
What do we think is healthy?
What is our current health status?
What defines our ideas
about who we are?
So when we think about food
in the digital age,
one of the biggest things that
has changed the way people eat
and the kinds of foods
that they are seeking out
are social media platforms.
Instagram, and the desire
for people to be able to take
beautiful food photos,
has transformed the idea that
you are what you eat
into you are what you post.
So we seek a lot of different things
from the food that we eat.
We can seek comfort, we can seek
a connection to history,
to our families, to our heritage.
But we can also seek
in it a sense of control.
When we live in
moments that are
full of economic,
political and social strife,
sometimes we seek in food
that sense of security and safety.
So in those moments,
we sometimes see people
get really interested in ideas
about naturalness, health and purity,
as a way to protect ourselves
from contexts outside of our control.
So food also tells stories
about who we are.
The full complexity
of our identity.
What we eat tells stories
about our gender and our sexuality,
our race and our ethnicity,
our social class,
or our aspirations
about our social class,
the region where we live,
even whether we live
in an urban or a rural area.
What we eat tells these
contradictory, complex stories
about who we are.
In the future,
we can use our knowledge
of what is happening in our brains
to design foods
that are low in calories and are
still attractive, but healthy. 
And we can help ourselves
by understanding
how our reward neurons
plot to get what they want. 
We can be aware of times
that we tend to make poor choices,
like when we choose a food
because of some label
which appeals to us,
rather than because of its taste. 
So in the end,
we are at least not fully
at the mercy of our reward neurons.
We can use our understanding
to help design healthy foods
and make healthy choices.
