We have all heard the expression, Don’t go shopping on an empty stomach. The common wisdom is that if you’re hungry and you go grocery shopping, you’re likely to buy that king size bag of Doritos and the gallon of ice cream instead of (or at least in addition to) the carrots and rice cakes.
As it turns out, there’s truth in the old adage. What’s really interesting is that it applies to much more than grocery shopping.
Researchers have been compiling strong evidence that links food to money. Whether or not we have been taking in adequate calories appears to have an important influence on the kind of economic decisions we make.
Food as the fuel of willpower
At the most basic level, food is fuel. More specifically, food provides us with a source of glucose (sugar), which is the primary ingredient our cells need to function properly. Our brains, which comprise only about 2% of our body mass, use about 20% of the calories we consume. Think about how you feel if you haven’t eaten in an unusually long time. Many of us become cranky and lethargic.
Oscar Wilde quipped that he could resist anything but temptation. Perhaps he was just hungry.
We also become weak-willed.
In a series of studies published over the last several years, researchers from the University of Florida and their colleagues, examined the effect of low blood sugar on how people make decisions. What they found is that the level of glucose available to our brains has a direct impact on our will power. After giving some experimental participants a soft drink with sugar and some an artificially sweetened drink, they put people in situations where they had to resist temptation or perform difficult tasks. People who received the real sugar drink were much better at resisting temptation and staying at hard tasks longer.
Resisting temptations takes will power, and the fuel of will power is glucose.
These results suggest why it is so difficult to stay on a diet. When you are restricting your caloric intake, you may be weakening your ability to resist temptation. The diet itself may be reducing your ability to diet.
When you are hungry, the future goes on sale
Economists use the term future discounting to refer to the extent to which a person is willing to accept a small gain now rather than hold out for a bigger gain later. In other words, how much more do we value what is available immediately versus what we might get later. People who discount the future more put less value on what happens in the future compared to now. Future discounting is an important concept for understanding why some people invest in education, development, exercise and all the kinds of things that require giving up something today for the possibility of a better future — and some people don’t. People who discount the future also tend to rack up debt.
As it turns out, when our blood glucose levels are low, we discount the future more. If you go shopping hungry, the idea of adding a few hundred dollars to your credit card debt won’t seem as bad an idea as it would if you were well fed.
Our decisions are often influenced by factors that are beyond our control and outside of our consciousness. In this case, you probably would not connect low blood sugar to your spending on clothes and electronics. However, knowing that being hungry will influence your spending allows you to manage this influence better. Next time you are thinking of a trip to the mall or to the stores downtown, have a nice meal before you hit the shops. Doing so may save you hundreds or even thousands of dollars.
As with the food and money connection, our decisions are often influenced by factors that we are not aware of. At beyondthepurchase.com, we are interested in all of the influences on how people spend money. To find out more about how your personality and values influence how you relate to money and spending, we encourage you to take our hidden buying motivations test, Consumer Susceptibility to Interpersonal Influence Scale, and the Materialistic Values Scale and Experiential Buying Tendencies Scales tests and find out about your own values — as well as those of your friends. We think you may learn a lot about how you and why you spend your money the way you do.
At BeyondThePurchase.Org we are researching the connection between people’s spending habits, happiness, and values. To learn about your spending habits, what influences your buying behavior, and how you define the good life, first Login or Register with Beyond The Purchase.
This blog post was written by Kerry Cunningham, a graduate student in the Personality & Wellbeing Laboratory at San Francisco State University. Follow @kerryfc
