Research paper
Honselman CS, Painter JE, Kennedy-Hagan KJ, Halvorson A, Rhodes K, Brooks TL, Skwir K. In-shell pistachio nuts reduce caloric intake compared to shelled nuts. Appetite. 2011;57(2):414-417. doi:10.1016/j.appet.2011.02.022
Why we cite it
Companion to cpi09 testing a different mechanism: effort/friction rather than visual feedback. Shows that the physical act of shelling pistachios reduces caloric intake by 41% without reducing satisfaction — a larger effect than the 18% reduction from shell visibility alone (cpi09). Together the two papers demonstrate that foods requiring effort to eat produce meaningful calorie reduction through both friction and visual cue mechanisms.
DOI: 10.1016/j.appet.2011.02.022 · PubMed 21645565 · Publisher