Evolutionary Explanations of Food Preference Essay

Evolution is the change in inherited characteristics of biological populations over successive generations. The environment our early ancestors lived in must be understood to understand why they adapted to certain behaviours or characteristics. This environment is known as EEA (environment of evolutionary adaption). Natural history and science have found that our species has spent much of its life as hunter-gatherers so by looking at their role we can investigate food preferences from an evolutionary perspective. Early human diets consisted of what was around them at the time and what pressured them to eat it. Humans had a preference for fatty foods as it would have been adaptive as conditions in the EEA meant that energy resources were vital to survive until the next meal. In addition calories were not as plentiful and therefore fatty foods were vital. Gibson and Wardle conducted a food preference study by observing the food choices made of children. Children naturally preferred more calorific foods, suggesting the food choices to be innate as children have not been exposed much to other influences such as social or cultural factors as other age groups. On the other hand fatty foods have been proven harmful if eaten in excess and therefore counters the claim that they are beneficial, as a diet on fatty foods would not be possible for survival. However, early humans did not live to the age of humans today and it is in the later age where diseases come as a result of excess fatty foods. Human preference for meat is said to have occurred due to the large decline in forestry 2 million years ago as the nutritional source declined. Meat is rich in nutrients and therefore appropriate alternative food consumption. The diet consisted of mainly the brain and liver and kidneys as they were rich in nutrients. Foley and Lee compared primate eating strategies with brain size, and found those eating meat had larger brain size and greater intelligence then primates who didn’t eat meat. This tells us that it was evolutionarily favoured to eat meat as it allowed us to grow in intelligence and become who we are today. In addition, Stanford also found that when observing other primates eat, they would eat the brain or bone marrow. This supports human preference for meat as early humans also ate meat such as the brain due to its high content of nutrients. Never the less both these supporting studies both used other primates than humans to identify early human diets and eating behaviours. This however may not be generalizable as the differences between humans and other primates could be our food preferences, resulting in poor external validity. Although it is particularly impressive if a range of findings in different species are consistent. Taste aversion also known as bait shyness is a form of food preference derived from an adaptive response to food which is bad for you. The development of taste aversion is adaptive as it prevents the organism from eating foods which were harmful, and as taste aversion is still possible 24hrs after eating the food it allows slow releasing toxins or poisons from being detected. In contrast animals can be seen to have a preference for foods which have medicinal or beneficial properties. Garcia found when a specific flavour is presented with a thymine to a thymine deficient rat the rat acquires a taste towards the flavour, supporting the role of taste aversion in supplying food preference. Furthermore Seligman claimed different species evolved different learning abilities, which was called biological preparedness, which allows each species to find associations more easily than others depending on if it helps them survive. This evolutionary theory states that food preference is determined based on our innate characteristics which have helped us survive as a species. It fails to consider the current environmental or social factors such as the effect of cultural factors. For example our innate food choices do not cover our broad range of food likes and dislikes such as in the eastern world they have a large preference for spicy food but in the UK often it is not the case. Furthermore mood has been seen to affect food preference, such as Garg et al found when in a sad mood people eat more sweet snacky foods however in a happy mood more likely to eat healthy foods.