Weight Management


According to James Painter, PhD, RD, Chair of the School of Family and Consumer Sciences at Eastern Illinois University, the “Pistachio Principle” is caloric reduction withoutcalorie restriction. It is one of the many ways we can alter our environmental cues, allowing us to become more mindful and satisfied with our food choices.

In-shell Snack Slows Consumption

Dr. Painter has conducted two preliminary, behavioral nutritional studies which suggest that consuming in‐shell pistachios may help to slow consumption while empty shells may serve as a visual cue about how much has been eaten. In the first study people who consumed in‐shell pistachios ate 41 percent fewer calories than those who consumed pistachios without shells. This suggests that empty shells may be a helpful visual cue as to how much has been eaten – thereby potentially encouraging reduced calorie consumption. 1

Pistachio Shell Offers Visual Cue

In Dr. Painter’s second study, in-shell pistachios were consumed over an 8-hour shift. On the first day the empty shells were left on the desks as a visual “reminder” of consumption and on the second day the shells were removed. Participants who left pistachio shells on their desk reduced their calorie consumption by 18 percent compared to participants who discarded shells immediately after consumption. 1

Stealth Dieting Tips and Tricks

Here are a few of Dr. Painter’s tips and tricks to help “fool yourself full.” You can find “The Pistachio Principle” fact sheet with more of Dr. Painter’s tips in Client Resources.

  • Buy smaller portions

    Fool yourself thin by buying single serve chips and small-size candy bars in place of family bags.

  • Consider environmental factors and choose meal companions wisely

    Bright light and fast music can encourage you to eat faster and ultimately consume more calories. Also, eating with friends generally increases the amount you eat.

  • Keep impulse foods out of sight and inaccessible

    Put healthy snacks like nuts, fruits and vegetables in sight; and chocolate, candy and other unhealthy snacks in the cabinet.