Researchers who study how we make choices — of any kind — have some helpful ideas about getting us to eat better: Do's work better than don’ts.

If you want people to choose healthier foods, positive messages work much better than negative ones, according to study results from Cornell’s Food and Brand Lab.

Researchers reviewed past studies on the consequences of various public policies on nutrition. They found that messages that were framed positively and supported consumer choice were more successful than those that seemed negative or threatening, or were perceived as reducing choice in some way.

“It’s clear that people value freedom of choice. When policies seem to encourage good choices, rather than limit bad ones, we see a much more positive response,” said David Just, a behavioral economist at Cornell, in a statement.

Take a walk on the wild side — invite a strange green vegetable to dinner.

For example, a program with price changes framed as a tax on unhealthy items actually caused more people to choose the unhealthy items. When the price change was framed as a discount for healthy foods, the people wanted more of those items.

It's about psychology. When people feel like they are being told what to do or not do, or what they can or cannot have, they feel their freedom is being threatened, and they are going to do the opposite of what is desired. In other words, an important driver of consumer demand appears to be rebelling against offensive policies, and this must be taken into consideration when making public policy recommendations if they are to be successful.

“Many decisions that we make are not totally rational,” said Just. “When trying to impose any sort of change, it is important to try and empathize with [your] audience and to work with, rather than against, the targets of that policy.”

How the nutrition policies are presented makes a big difference in the ultimate effectiveness of those policies. Public health officials and lawmakers need to find ways to use this information so future public policy recommendations about nutrition draw on people’s positive emotions and encourage all of us to make healthy food choices.

So, rather than continuing to tell consumers they need leafy greens to have a healthy diet, maybe we will see a campaign to “Take a walk on the wild side — invite a strange green vegetable to dinner.”

The study was published in the American Journal of Agricultural Economics.