The more current the currency, the better kids eat,  according to a study that looked at how payment methods in public school lunch systems affect food choices.

Fries or Fruit

Fries or fruit, the decision may be influenced by how you’re paying.

The study, by Cornell researchers funded with a government grant, looked at two types of payment methods in public school cafeterias, those that accept only pre-loaded debit cards and those that accept cash or debit card.

Like other studies comparing cash and debit card spending, the study found that students spent more carefully when cash was involved. But the quality of those purchases also changed depending on how they were being paid for.

Students in the cash/debit cafeterias, where at least a portion of the kids were using cash, bought more fruits and vegetables (47 percent vs. 31 percent in the debit-only cafeterias) and fresh vegetables (31 percent vs. 11 percent in the debit-only cafeterias.)

The immediacy of the spending (cash vs. a card), seemed to have an impact on food choices. Researchers hypothesized that when the students were more aware of their spending, they were also seemingly more attuned to the consequences of their food choices.

In other words, the immediacy of the spending seemed to serve as a reminder or trigger for considering the healthfulness of the food. One  sneaky factor may have been that the kids were more aware that they were spending mom and dad’s money.

But there was another factor in play. Limited by a finite amount of cash in hand, versus a debit card backed by a fuzzy and deep well of cash, students were more likely to buy the full meal deal offered in public schools. The full meal, an entree with vegetable and fruit sides is a better value, more food for the money, and also healthier, because it follows government guidelines. This was another facet tilting the kids toward choosing better foods.

Those with with debit cards, by contrast, were more likely to buy more expensive, and less healthy ala carte items, fried sides and sweet desserts.

Here’s a synopsis from the study, published in the journal Obesity:

Without debit cards, students use cash to purchase lunch, in most cases provided by their parents. Those receiving the free lunch would only be allowed to purchase the standard lunch under either system. For those not receiving the free lunch, parents may give their child just enough cash each school day to purchase the standard lunch. Thus, in order to buy a la carte items, which are often less healthy options, a child must forego purchasing the standard lunch. Spending is limited to the amount of money physically present in hand. Alternatively, with debit accounts, a child is typically endowed with a large amount of money that can be drawn down daily. Parents pay for several weeks’ or months’ worth of lunches in advance, resulting in little to no control over individual transactions. With such large sums of money, it may be difficult for parents to gauge how long the money should last if spent wisely. This may lead children to generally greater spending on lunch.

The researchers concluded:

School payment systems with cash options are associated with a lower purchase incidence of less healthy foods and higher purchase incidence of more healthy foods. It should be noted that some debit systems (e.g., NutriKids®) allow parents to set daily limits on spending or to restrict purchases of certain items. Such systems still provide schools with convenience while allowing parents to guide or control student lunch choices. . . .

Importantly, these results point toward payment systems as being a potentially overlooked means to guide the selection of foods in schools. If the use of cash versus credit or debit cards can nudge a student into making slightly healthier choices, there may be a wide range of interventions—such as a “cash for cookies” policy—that encourages students to think twice before making their selection. More work, including experimental studies, is needed to examine the long-term impacts of various debit systems on student purchases and determine whether this association is causal in nature.