Ig Nobel Prize winner Brian Wansink (honored in 2007 for exploring the seemingly boundless appetites of human beings, by feeding them with a self-refilling, bottomless bowl of soup) has conducted an experiment with potato chips. The Cornell Chronicle (with this photo taken by Robin Wishna) reports:
red chips were interspersed at intervals designating one suggested serving size (seven chips) or two serving sizes (14 chips); in the second study, this was changed to five and 10 chips.
Unaware of why some of the chips were red, the students who were served those tubes of chips nonetheless consumed about 50 percent less than their peers: 20 and 24 chips on average for the seven-chip and 14-chip segmented tubes, respectively, compared with 45 chips in the control group; 14 and 16 chips for the five-chip and 10-chip segmented tubes, compared with 35 chips in the control group.
BONUS (about potato chips): The 2008 Ig Nobel Prize in nutrition was awarded to Massimiliano Zampini of the University of Trento, Italy and Charles Spence of Oxford University, UK, for electronically modifying the sound of a potato chip to make the person chewing the chip believe it to be crisper and fresher than it really is. [REFERENCE: “The Role of Auditory Cues in Modulating the Perceived Crispness and Staleness of Potato Chips,” Massimiliano Zampini and Charles Spence, Journal of Sensory Studies, vol. 19, October 2004, pp. 347-63.]