In-Shell Pistachios Promote Satiety, Mindful Eating

BOSTONEating in-shell pistachios helps consumers become more mindful of their snacking behaviors, reducing overall calorie intake without feelings of deprivation, according to new studies presented at the American Dietetic Association's annual Food & Nutrition Conference & Expo (FNCE).

"The research shows that our perception of how much food we need to become satiated and maintain a healthy body weight is skewed by many environmental factors," said Dr. James Painter, a behavioral eating expert and professor and chair of School of Family and Consumer Sciences at Eastern Illinois University. "We eat more food if we eat off of a bigger dinner plate; we'll eat more potato chips if they come in a larger bag." Painter added that mindless eating essentially means we are ignoring hunger cues that tell us to stop, but said that small behavioral changes can help people eat less without feeling deprived.

In the first study, 140 subjects self-selected a portion of pistachios as they entered the classroom and the weight of the selected portion was recorded. At the end of class, the weight of the remaining pistachios was recorded and subjects were surveyed to determine their fullness and satisfaction.

In condition one, the subjects were offered in-shell pistachios and consumed an average of 125 calories. In condition two, subjects were offered shelled pistachios and consumed an average of 211 calories, a difference of 86 calories. Those who snacked on in-shell pistachios consumed 41-percent fewer calories compared to those who snacked on shelled nuts and fullness and satisfaction ratings were not significantly different. The shell changed the package of the pistachios, adding volume and it slowed consumption, allowing for hunger cues to be activated, reducing overall calorie intake.

In the second study, 118 subjects were offered pistachios to eat at their desk over an 8-hour period beginning each day with a 16-ounce bowl filled with 4 ounces of in-shell pistachios. Another 16-ounce bowl was provided to place the empty shells. Every two hours pistachios were added in 2-ounce increments, as needed. In condition one, the shells remained in the bowl until the end of the day and subjects consumed an average of 216 calories. In the second condition, the bowl with empty shells was emptied every two hours and subjects consumed an average of 264 calories, a difference of 48 calories. In the first condition subjects ate 23 percent fewer calories, yet fullness and satisfaction ratings were not significantly different between conditions.