Pistachios are related to the mango fruit and the spice sumac.
Weight Wise
The Weight-wise Nut

Researchers at Loma Linda University conducted nut feeding trials in which free living individuals substituted nuts for 20% of their total calories. The lead researcher, Joan Sabaté MD, PH.D., found that, despite the fact that nuts contain fat and are energy-dense foods, they did not cause an increase in body weight.
These results for pistachios are consistent with studies of other nuts and body weight. So pistachios are not only delicious, they’re also a great alternative to other less healthy snacks.
Fiber-tastic!
Pistachios are a good source of dietary fiber and are among the highest fiber nuts, providing 12 percent of the daily value per 30 gram serving (about one ounce). The Dietary Guidelines for Americans recommends a dietary fiber intake of about 14 grams per 1000 calories; consumption studies have indicated that Americans typically consume only half of the recommended amount.4-5 As one of the highest fiber nuts, pistachios can help meet this goal.
In-shell Snack Slows Consumption
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 without calorie 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.
Dr. Painter completed two studies that found that individuals could reduce their overall calorie consumption without consciously restricting their diets. Interestingly, despite the reduction in calories, they reported feeling equally as satisfied as the control group that consumed more calories.
In his first study, individuals self-selected either in-shell or shelled pistachios. Because the shells act as a natural barrier, taking longer to remove, the in-shell group consumed 50% less than the shelled nut group. And yet they reported feeling equally as satisfied as the group consuming more.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. Results showed that when the shells were left on the desk as a visual cue subjects consumed 35% fewer calories.