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Food preferences can be explained by the environment of evolutionary adaptation (EEA), where we
acted as hunter-gatherers and food supply was inconsistent. Because we were uncertain about our
next meal and would use energy searching whether we found food or not, we tended to favour
energy-dense foods, which were typically sweet and fatty. Because this aided survival, it has
become a basic instinct for us to favour these.
This preference for energy density was beneficial in the EEA due to the unpredictable food supply.
However in the modern world, this was become maladaptive; we have the same drive to eat but
food is available constantly and we do not have to search for it. This can lead to overconsumption
and, consequently, obesity.
This is supported by Gibson and Wardle, who offered 4-5 year olds fruit and vegetables. They found
that the children naturally preferred energy-dense foods, such as bananas and potatoes. This shows
that we have developed an adaptive preference for energy density as it helped us survive in the
Support also comes from Sclafani and Nissenbaum, who offered rats cherry energy-dense drink and
grape plain water. When the rats were later offered plain water in both flavours they showed a
preference for the cherry flavour. This suggests that rats have adapted to learn which food is
energy-dense and later identify it by its flavour, like how we associate sweetness with energy.
Evidence for these preferences has been shown by Berridge, who identified a pleasure response
involving lip smacking in response to sweet flavours. This was found in newborn babies, as well as
other species such as monkeys. Since newborns don't have time to learn responses, this suggests we
have an innate preference for energy-density.
However this isn't the only explanation as evolutionary preferences can be overwritten by culture.
Kimchi (a type of pickled cabbage) is popular in Korea despite its low energy and lack of sweetness.
This suggests that evolutionary explanations do not take environmental factors into account, only
addressing our nature and not our nuture.
Evolution also explains food avoidance as in the EEA, poisonous foods tended to have a bitter, sour
flavour. An innate taste aversion is adaptive as it prevents us from poisoning ourselves, and this is
further reinforced by a `near miss'. If we try a new food and become ill from it, this gives us negative
reinforcement and we learn to avoid it.
This is supported by Berridge, who has identified an innate aversion response in newborn babies and
other species which involves screwing up the face when tasting bitter flavours. This shows evidence
of an inborn aversion to bitter tastes, meaning these would be avoided and survival aided.
Food neophobia (fear of new food) would have been adaptive in the EEA as reluctance to try new
food acts as a defence mechanism against poisons, providing a protective evolutionary advantage.
This is also present in bait shyness, where rats only eat a small amount of a new food. If they become
ill, they then learn to avoid it.
Evidence of neophobia in children is provided by Cooke et al., who found that 4-5 year olds with
neophobia ate less fruit, vegetables and protein than their peers. The idea of the `fussy eater' in our
modern world shows evidence of food avoidance in the EEA, which would have aided survival.
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A study which supports bait shyness in rats was carried out by Garcia et al., who gave rats a sweet
flavoured food as well as a dose of radiation to make them feel ill. When later offered the food
again, they avoided it. This suggests that they began to associate the food with feeling ill and so
developed a learned taste aversion, supporting the theory.…read more