Food Choice: Disgust, pain and preferences

Food choice is a complex issue. At one level, we share the same biology as all animals as regards hunger, appetite and satiety. Rat studies can thus explain some of the mechanisms but they fall far short of the bigger picture because humans have a large and very complex frontal cortex, which governs all the things that make us human and not rats. It is through the cortex that we think, learn, speak and assimilate and disseminate complex ideas. More than anything else, these attributes allow us to divide labour and live in a sophisticated society and that society itself plays a major role in food choice.

In lecturing my students on food intake, I ask them to close their eyes and to think of some occasion when they were really hungry. I then tell them that when they open their eyes, the PowerPoint slide will show a food and I want to know would they eat it.  Invariably, they indicate their refusal to consume the food, which is a very nice bowl of highly nourishing and succulent cat food. They do agree that if the choice was between staying alive and eating the cat food, then they would eat it and just hope not to gag. Having recently read “How Pleasure Works” by the Yale professor of psychology, Paul Bloom, I now know that the reaction of my students is one of disgust. I also learned from Bloom that disgust is not a property of the cat food but a socially conditioned belief. Quite simply, I know of nobody and, dear reader, I would bet you know of nobody, who eats cat food. The cat food is nutritious, safe, made from high quality ingredients by branded companies for highly fussy pet owners. So there is nothing inherently disgusting in cat food. It’s simply a disgusting thing to eat by our social norms. Rats would have no qualms in eating cat food. Eating insects is disgusting to us but not to many nomadic tribes and eating pork is disgusting to a devout Muslim but not to the majority of Irish people. Paul Bloom goes on to point out that whereas society decrees what is acceptable to eat, within that framework, individuals can show disgust or more correctly, aversion to specific foods and, in general, such aversions can be related to some life experience. Thus I like fish but if given a choice, I would not eat mackerel. I still recall the stink in our kitchen at home when my father would head, tail, gut and fillet a bucket of mackerel for grilling, which he and his mates had caught in Dublin bay.

Bloom also raises another aspect of social influence on food choice: pain. Now it might seem strange to write about pain in a book on pleasure but so long as the recipient is in control of the situation, mankind likes a little bit of pain. We go to horror movies, which can be terrifying and we take amazing risks on crazy rides in amusement parks. In foods, we eat chilies and although our taste buds tell us not to do so, we overcome these because society decrees some consumption of chilies to be worthwhile. Thus in Mexico, where chili consumption is high, children are gradually weaned on to a high chili diet. Such a diet in earlier times helped give an identity to a group in much the same way as their language, music or dance did. You can imagine the fun these people had when a stranger was given their hospitality only to scream for water to cool their burning palates!

Let us now return to the physiology of taste and flavour and see how that competes with social pressure. Paul Bloom draws on a joint study carried out by the business schools at MIT and Columbia. Subjects were asked to taste two beers: a regular Boston brand or a “new” MIT beer. The latter was no more than the regular Boston beer with a dash of balsamic vinegar. The first group (the control group) were not given any information at all and simply asked which brand they preferred. They voted 60:40 for the “new” MIT beer The second group were told that the regular Boston beer was to be compared to a “new” MIT brew and they were told that this beer was just the regular beer plus balsamic vinegar. Now the vote was only 20% for the MIT brew. A third group was treated like the control group but immediately after they had drunk it and before they expressed their preference, they were told the truth: that the “new” MIT beer was just ordinary beer with balsamic vinegar added. They voted like the control – 60% preferring the MIT brew. Clearly, the latter group, like the controls, formed an opinion that if a beer came out of MIT it must be good. Having now made their minds up, the third group stuck to this assumption even though they knew that it was just a stupid concoction. The values we give to foods in making food choice are very complex. The idea that a beer from MIT had to be good goes hand in hand with our preferences for brands. Indeed, Bloom points out that studies show that Coca Cola drinkers enjoy Coke more when the glass is a Coke branded glass. Status is very important in food choice because, like the peacock’s tail, it is a symbol of ones power and status.

Rat studies are thus of limited use in understanding food choice. They might explain the mechanisms, which determine the desire to eat but not food preferences. They are socially determined to a great extent. The simpletons of public health nutrition reduce the obesity issue to a higher probability of choosing some food such a sugar sweetened beverages or fast food because that’s the simpleton’s fashion – simple and stupid. Some people make the conscious decision to take up smoking or alcohol intake. But nobody wakes up and says:” Guess what. I’m going to get fat”. It happens and we know so little about how that passive accumulation of energy occurs and how our food preferences promote this weight gain. We need less research money spent on studying why rats chose to eat or not and more money spent on human behavioural sciences, particularly food choices and preferences.