Environment of evolutionary adaptation (EEA) (AO1)
The survival of our ancestors depended on them getting the right nutrients. We need to understand the environment out ancestors lived in to understand the problems they faced. EEA is the environment that they lived in and evolved from. It is believed our ancestors lived in hunter-gatherer societies and the first emergence of people were know as Australopithecus, about 3.5 million years ago in the African Savannah.
Taste aversion (AO1)
It is also important that we learned what was edible and what was poisonous.
Garcia et al (1955) found that rats learned to avoid Saccharin (rat poison), they learned that after tasting it, it made them ill, so avoid it. It can take up to 24 hours to learn after eating the food. This shows that if our ancestors did eat something that didn't kill them, then they would learn to avoid it.
It has been suggested that we not only learn about taste but odor too.
Taste aversion (AO2)
Seligman (1970) argues different species evolved and learned different abilities, he called this biological preparedness. This helped individuals survive.
This helps to explain why we avoid certain foods, for example, cancer patients undergoing chemotherapy can experience gastrointestinal. Therefore they associate the foods they eat with illness/treatment.
Bernstein and Webster (1980) gave patients a novel tasting ice cream and found that they associated the novel ice cream to the chemotherapy.When the patient was given familiar and unfamiliar food to eat, they foud that the unfamiliar food was associated with the chemotherapy. This is known as neophobia.
Early diets (AO1)
In pre-agricultural societies, where food was limited there would have been a problem of finding enough food to eat. Therefore they would have had to evolve in a way to store as much energy as possible, this is believed to have lead to binge eating as a adaptive solution. Sweet, fatty and salty foods were preferred as they store the most energy, so they can survive until the next meal is found. It makes sense to store as much calories as possible and burn as little as possible as it was unknown when the next meal was.
The preference for meat may have been due to the decreasing forestation and grass land in Africa, which meant the need for a new food source. This is also the time when the brain started to develop. As the brain developed it needed protein to grow.
Milton (2008) argues without meat it is unlikely that we would have developed the modern brain size.
Calories in early diet
Gibson and Wardle (2001) found evidence that we have an evolutionary preference not for sweet things, but for those high in calories. This has been found as 4 and 5 year old children have been found to prefer food that are high in calories.
Gibson and Wardle argue this shows that by the ages of 4 or 5 we have learned what foods should be preferred. Therefore it may not be due to innate preferences.
Humans were vegetarians?
Cordian et al (2006) believes that humans gained calories from other things, not just animal fats. This suggests that out ancestors had healthy diets and were vegetarians.
However, there is no evidence to support this theory. Anthropological evidence (e.g. Abam (1987)) show that all societies prefer meat. It is also not possible for them to have been complete vegetarians, this is because they would not have consumed enough calories the from plants and grains available.
Are all food preferences important?
Many of the diets our ancestors had is no longer needed for modern life. This includes eating animals for calories, this is because we have easy access to food and no longer need to store energy. We also now eat healthier things, like those yogurts that reduce cholesterol levels. Today we tend to eat and live more heathier lifestyles.
There does seem to be a universal preference in the foods we eat, we like to eat sweet foods as children and later fatty and salty foods. However, it does not explain why the food preferences that develop after infancy. For example, spicy foods were initially rejected, but now chilli is the second most popular food in the world. It is believed that culture modifies our food preference as we grow up.
If our ancestors had not eaten the right foods they would have died off, along with their food preferences, therefore the foods preferences we have in cultures must have been kept as they helped us survive.
Issues, debates and approaches (AO3)
Explains why there is a obesity problem, due to the evolutionary need to retain calories and expel as little as possible.
Theory can be argued to be reductionist, as it oversimplifies everything to evolutionary mechanisms, therefore ignoring the psychological factors like emotion.
Nature and Nurture
There is evidence of innate food preferences and also food preferences that are influenced by our cultures.
The approach overlooks freewill and conscious cognitive and social factors (e.g. dieting, social learning.)