University of Michigan study: Time to leave leftovers at the table

Posted at 9:42 AM, Sep 05, 2018
and last updated 2018-09-05 10:44:37-04

With food portion sizes increasing, losing weight by just eating half of what's on your plate and saving leftovers for later may not help, according to a UM study.

The study says the average portion and package sizes have increased over time, leading to increased consumption.

"We know that growing portion sizes increase consumption, but grossly enlarged portions also cause consumers to face more and more food leftovers," said Aradhna Krishna of the University of Michigan Ross School of Business. "Our research reveals that unconsumed food can exert meaningful influence on people's perceptions, affect, motivation and important health-related behavior."

Findings from five studies showed larger leftovers caused people to eat more "in a subsequent  unrelated food consumption task" and exercise less "in an explicit calories compensation task."

Eating leftovers leads to the perception that a person is consuming less because they are only eating half of their original meal. 

"The psychological drivers of this phenomenon are twofold," Hagen said. "Larger leftovers reduce perceived consumption, which leads people to feel better about themselves. And feeling better about themselves, in turn, reduces people's motivation to compensate."