38 | New Scientist | 1 January 2022MIODRAG IGNJATOVIC/GETTY IMAGESThe way we think about what we
eat determines how satisfying we
find certain foods, with knock-on
effects for our weight.
Consider the following
questionnaire. On a scale of 1
(strongly disagree) to 5 (strongly
agree), do you think that:- There is usually a trade-off
between the healthiness
and tastiness of food - There is no way to make
food healthier without
sacrificing taste - Things that are good for
me rarely taste good
Researchers have found a
correlation between responses
to these statements and people’s
propensity for weight gain: the
more strongly they agree with
these three statements, the greater
their body mass index tends to be.
In the past, some people might
have imagined that this was
because of low self-control –What’s your food mindset?
before – a more distant event that would
have little effect on their feelings of satiety
in the moment. Instead, it was expectations
of current satiety, based on the recent
memory, that mattered.Mind over menu
Aside from memory, other contextual factors
seem to shape our expectations of satiety,
including the information we are given
about a meal’s contents. Researchers at the
University of Aberdeen, UK, invited 26 people
for an omelette breakfast on two occasions.
Before they ate, participants were shown the
ingredients. This was, ostensibly, to check
whether they had any allergies – but the real
purpose was to change their expectations.
On one occasion, they were shown two eggs
and 30 grams of cheese; on the other, they
were shown four eggs and 60 grams of cheese.
In reality, the participants all ate the same
portions – three eggs and 45 grams of cheese –
for both breakfasts. But the initial presentation
did affect their subsequent appetite. People
who had seen the smaller pile of ingredients
subsequently ate more pasta from a buffet at
lunchtime than those who believed they had
already consumed a hearty meal.
Similar patterns could be seen in people
drinking smoothies. In another small study,
participants who thought they had consumed
a large quantity of blitzed fruit tended to be
less hungry over the following 3 hours than
those who had seen a smaller portion.
Of course, we don’t always get to see the
original ingredients in meals, especially in
ready-made food, but labelling can influence
our appetite through similar mechanisms.
Many people associate the word “healthy”
with “unfulfilling”, for instance, which reduces
their expected satiety (see “What’s your food
mindset?”, left). When a group of study
participants were each given a “healthy”
chocolate-flavoured protein bar, they
subsequently felt hungrier than people
who had eaten the same bar when it was
labelled “tasty”. Indeed, the association
was so strong that they felt hungrier than
people who had eaten nothing at all.“ People who ate a ‘healthy’
chocolate-flavoured bar felt
hungrier afterwards than people
who had eaten nothing at all”
New Scientist Live
Hear David Robson discuss the power of mindsets
at our festival of ideas live.newscientist.comthey simply didn’t want to give
up the pleasure of food. But these
kinds of attitudes may create an
expectation effect on people’s
appetites, so that the mere sight
of “healthy” on a food label sets
someone up for lower satiety after
they have eaten a lower calorie
meal (see main story). This would
leave them feeling hunger pangs,
making dieting much harder.TV dinners could lead you to
forget what you have eaten
and feel hungrier as a result