By now you’ve heard the news—nuts are not an evil bar food waiting to clog your arteries and grow you a gut. In truth, we know, nuts are not only delicious, they also provide protein and give you energy, and may play a role in health and longevity.
But there’s more great news. One type of nut, by Mother Nature’s design, stands out from the pack: It’s the pistachio, a great-tasting snack that also turns out to be a powerful weapon in the fight against mindless eating.
When you’re in the gym benching more than your body weight, it’s hard to imagine that the task of popping a pistachio out of its shell could be key to hitting your fitness and weight goals. But shelling the nuts—and keeping the shells in view—may slow snacking and help you take in fewer calories than you would eating out-of-shell nuts (like almonds or cashews).
The concept has been deemed the “Pistachio Principle,” and it’s the brainchild of behavioral eating expert James Painter, Ph.D., R.D., professor at the School of Family and Consumer Sciences at Eastern Illinois University. In one of his behavioral experiments at the university, whose preliminary findings were published in 2011 in the journal Appetite*, snackers who ate unshelled pistachios took in 41% fewer calories than those who ate nuts that had already been shelled. (Those who ate pre-shelled pistachios consumed an average of 211 calories, while those who had to shell their own ate an average of 125 calories.) What’s more, those who ate fewer in-shell nuts reported essentially the same levels of fullness.
In another preliminary Eastern Illinois study, subjects who sat at a desk all day with a bowl of pistachios (which was refilled every two hours) as well as a shell bowl ate 18% fewer calories than those whose shells were taken away when the bowl was refilled. Though further research is needed, these two studies underscore pistachios’ value as a great everyday snack.
Pistachios are also a good source of protein and fiber, as well as vitamin B6, copper, and manganese.
“Association of Nut Consumption with Total and Cause-Specific Mortality,” Bao, Y., Han, J., et al, New England Journal of Medicine, 2013; 369;21: 2001-2011