Pistachios in the shell could be your best bet for a nutritious snack, says Dr. James Painter, behavioral eating expert and chair of Family and Consumer Sciences at Eastern Illinois University. He conducted two studies, published in the journal Appetite, to determine if the shell had an impact on the amount of the nuts consumed. Yes, the shelling takes effort, but it all pays off.
Pistachios are one of the lowest-calorie nuts, with 160 calories per 30-gram serving -- approximately one ounce -- and pistachios yield the most nuts per serving: 49 pistachios in a one-ounce serving compared to just 23 for almonds.
"Nuts are great -- they have a lot going for them nutritionally," Painter says. "Pistachios, walnuts, almonds, all good. It's good to have a variety, as each nut brings something different to the table. In particular, pistachios have the highest antioxidant capacity compared to popular snack nuts. Their green color, provided by lutein and zeaxanthin, is distinct to pistachios. Pistachios are one of the lowest-calorie nuts and they are one of the lowest-fat, too."
In the first study, a sample of college students, ages 18 to 24 years old, were assigned to consume either in-shell or shelled pistachios during class time. Participants from each class were tested on two different days, one day in each condition. Half began with the shelled pistachios and half began with the in-shell pistachios.
Those who chose shelled pistachios consumed an average of 211 calories, while those who chose in-shell pistachios consumed an average of 125 calories – 41 percent fewer calories.
In the second study, a sample of 118 faculty and staff from a Midwestern university were offered pistachios on their desks for eight-hour periods on two days and could consume the pistachios at their leisure during that time.
Each day began with a 16-ounce bowl filled with four ounces of pistachios in the shell and a second 16-ounce bowl to place empty shells from the pistachios consumed. Pistachios were added in two-ounce increments every two hours.
For the first group, the bowls with pistachio shells were not emptied until the end of the day. For the second group, the bowls with pistachio shells were emptied every two hours.
Researchers found that the empty pistachio shells can actually serve as "visual cues" as a reminder of consumption. Study participants who left pistachio shells on their desk consumed 22 percent fewer calories than those whose shells were removed.
How can we develop more mindful eating so we don't overeat and pack on unnecessary pounds?
"First, we need to change the dieting environment to help us eat less without even knowing it, such as choosing nuts in a shell," Painter says. "The shells simply slow eaters down, causing us to consume less in the same amount of time as other snacks. Second, people need to be more mindful each time they eat and be more aware of what they are putting in their mouth."
Painter keeps packages of pistachios and raisins on hand for himself. "I have always liked nuts and dried fruit as a desk-side snack because they are convenient and do not spoil. They simply last and they taste good."
And you'll see personalized content just for you whenever you click the My Feed .
SheKnows is making some changes!