The Pistachio Effect – New Research Reveals We Can Get "Beach Body Ready" By Shelling Nuts
According to leading New Zealand nutritionist Angela Berrill, people who eat nuts straight from the shells could cut down on their calorie intake by 40 percent each time.
New research has revealed when people have to remove the shells from pistachio nuts they are encouraged to eat less because the physical labour of opening them helps slow consumption. The discarded shells also offer a visual reminder of exactly how many nuts have been eaten.
“When people are aware of the quantity of food they are eating, as opposed to mindlessly snacking, they are more likely to eat a healthy portion,” says Angela.
The term, the Pistachio Effect, was coined by Dr James Painter, a behavioural eating expert professor and Chair of School of Family and Consumer Sciences at Eastern Illinois University. He believes we can alter our environmental cues, allowing us to become more aware of the quantities we are eating.
Dr Painter undertook two separate studies with 140 university students, who were given pistachios as they went into lessons. Half of the students were given the nuts still in their shells, while the other half were given shelled nuts. At the end of class Dr Painter discovered that those eating the shelled version had consumed an average of 211 calories each, while those who had to shell the nuts as they ate them consumed an average of 125 calories each.
Despite the reduction in calories, both groups of students reported feeling equally satisfied and full. Dr Painter believes this comes down to two factors:
1) Slower consumption: The shells act as a natural barrier, taking longer to remove, therefore the in-shell group consumed less than the shelled nut group
2) Visual cue: The empty shells were left on the desks and acted as a visual reminder of consumption, reminding the students of how many they had consumed, therefore helping them resist from over-eating
Although having a visual reminder can be helpful when attempting to incorporate nuts into the diet, Angela points out that there is a place for shelled nuts, as long as appropriate amounts are eaten.
"Even foods, like nuts, which we consider ‘healthy’ should be eaten in moderation," says Angela.
"While eating shelled nuts has been proven to help reduce the total amount of nuts, and therefore calories, consumed, it is recommended to moderate your intake. Rather than taking a large bag of nuts to work with you, try measuring out a small handful (30g) into a small zip-lock bag or container before you leave the house. This will ensure you don't over-indulge, while still enjoying all the health benefits that raw nuts provide."
Although it is important not to eat too many nuts, as they are an energy-dense food, pistachios along with all other types of raw nuts can play an important part in a healthy diet. Among other benefits, they can lower the LDL (low-density lipoprotein or "bad" cholesterol level) in your blood, and may help improve skin and hair health. Nuts also provide the body with much needed fibre and protein, which helps to keep our hunger satisfied between meals.