Just in time for the holidays, new research explores our tendency to overeat when we only have a little bit of food left over – and how we justify it by convincing ourselves that it’s not as unhealthy as it is. Vanderbilt marketing professor Kelly Haws calls her latest research “Justifying by Healthifying,” in the journal Appetite.

“Many of us were raised with this ‘clean your plate’ mentality, stemming from a desire to ensure one is not being wasteful or their children are eating well; however, this can also lead to overconsumption,” Haws said. “So, one could argue that good advice for someone trying to manage their food intake would be not to clean their plate.”

Haws and her co-authors were interested in exploring how the clean-plate phenomenon, called “consumption closure,” affects our desire to keep eating more than we should or want to when there’s just a small amount left, “The questions we had were: Is there something special about having this small quantity left over, and what processes do people use when justifying continued consumption or deciding whether or not to continue consuming?”

Haws, Anne Marie and Thomas B. Walker, Jr. Professor of Marketing at Vanderbilt University’s Owen Graduate School of Management, studies consumer behavior, with a particular focus on food consumption behaviors and food decision-making.

She and her co-authors, Veronika Ilyuk of Hofstra University and Lauren Block of Baruch College, conducted several experiments involving asking participants to eat or imagine eating a variety of unhealthy foods—cookies, chocolate-covered almonds and pizza—and then answer questions designed to tease out how hungry they were, how much more they wanted to eat, and how healthy they believed the food to be in each scenario. They found:

That last cookie is very tempting.

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