Discuss evolutionary explanations for food preferences.

(8+16)

AO1 Bitter Taste

An example of an evolved food preference is that the experience of bitter taste has evolved to detect potentially harmful toxins in plants. Sandell and Breslin (2006) screened 35 adults for the bitter taste receptor gene. Those with the sensitive form of this gene were more likely to experience toxic glucoseinolates as bitter, which would explain why such genes are widespread In modern times.

 

AO1 Fatty Foods

Preference for fatty foods was so adaptive because the harsh conditions faced by early humans in the EEA meant that foods that provided energy resources were vital to survive. Early humans would therefore have evolved a preference for calorific rich foods, such as meat. A meat diet was full of nutrients, and became the catalyst for rapid brain growth.

AO2 

There is research support for the evolved preference for high calorie foods. For example, Gibson and Wardle et al tested the preferences for specific fruits and vegetables among 4-5yearolds. They predicted that children would prefer foods that were rich in calories (such as bananas and potatoes) over other foods, which is what they found.

AO2 /IDA

Evidence from comparative studies of closely related non-human species has supported the importance of saturated fats in the diets of early humans. Stanford studied chimpanzees in Gombe National park. When these animals were close to starvation and managed to kill a monkey to eat, they went straight to the fattiest parts (e.g. brain) rather than the more nutritious flesh.

AO2

The Importance of calories in early humans’ diets is challenged by Cordain et al. (2006) who claimed that early humans obtained calories from sources other than animal fats, and may even have been vegetarian. However, this in turn has been challenged by anthropological evidence, which has shown that all societies show a preference for animal fats suggesting that this is a universal evolved preference.

AO1 Taste Aversion

Taste aversion is an evolved defensive mechanism that enables predators to survive encounters with prey with toxic defences. When early humans experienced nausea after consuming toxic prey they formed a long- lasting aversion to the taste and scent of this type of food. The medicine effect is a tendency for Individuals to develop a reference for any food eaten prior to recovery from an illness.

AO2

Garcia et al provides research to support taste aversion. He found that rats who had been made ill through radiation shortly after eating saccharin, developed an aversion to it and very quickly associated their illness with the saccharin.

AO2

A real-world application of taste aversion is to understand the food avoidance that is often found in children being treated for cancer. Some cancer treatments, such as radiotherapy and chemotherapy have the side effect of causing gastrointestinal illness. When this illness is paired with eating a particular food such as ice cream, a taste aversion to that food can result. Therefore this has resulted in the development of giving patients a novel food along with some familiar food prior to the chemotherapy in which the patient creates an aversion to the novel food.

AO2/IDA

The view that all food preferences are due to evolutionary factors is challenged by the fact that there are cultural differences in food likes and dislikes. Although there are some universal preferences, e.g. for sweet foods, these innate responses do not account for the broad range of food preferences found in different cultures. It is likely that these preferences (e.g. for spicy foods) developed because of cultural tastes and preferences.

IDA

The evolutionary perspective is both reductionist and determinist. The explanation is an oversimplification by suggesting that adaptiveness is the single, guiding principle. Such explanations are also determinist, as they propose that eating behaviour is determined by past environments, thereby overlooking the notion of free will and the fact that human behaviour is affected by many other factors such as thought, emotions and social factors.