Introduction
Dietary guidelines around the world recommend the regular intake of nuts because of their nutrient contribution to the diet and reported health benefits. However, consumers are often reluctant to include nuts in their diet due to the high caloric density of nuts. Clinical studies find no association between consumption of nuts and body weight, BMI, or waist circumference. The absence of weight gain among nut consumers in these studies suggests that they compensate by eating less of other foods, but the precise mechanisms remain unknown.

About the Study
In a 12-week randomized, controlled intervention, researchers looked at how adding a pistachio portion to the daily diet affects body weight and composition, satiety, energy and nutrient intake.

Sixty healthy pre-menopausal women who did not typically consume nuts were randomly assigned to a control or an experimental groups. Experimental participants consumed 44 g (250 kcal) pistachios mid-morning while the control group maintained their current eating habits for 12 weeks. Food intake and appetite sensations following the pistachio portion were assessed in all participants before and after the intervention in four, 2-consecutive-day test sessions.

Body weight and composition were unchanged in both groups after 12 weeks. The study found that women adjusted to the extra calories from the pistachio portion, by mostly reducing intakes of carbohydrates and starch, in parallel with less hunger and greater satiety following the morning pistachio snack. Intakes of healthy fats (MUFA, PUFA, linoleic acid), vitamins and minerals were significantly higher among women consuming the pistachio snack, in spite of compensatory adjustments in intake.

What the Findings Mean
Eating a handful of pistachios every day does not lead to weight gain but instead makes for a healthier diet with a better nutrient intake. The extra calories provided by the pistachios induce satiety and sufficient adjustment of intake to prevent body weight changes.

Marc Fantino, CreaBio Rhône-Alpes® Centre Hospitalier Montgelas, Givors (Grand Lyon), France

France Bellisle, Equipe de Recherche en Epidémiologie Nutritionnelle, Centre de Recherche en Epidémiologie et Statistique Paris Cité, INSERM U1153, INRA U1125, Cnam, Université Paris 13, 93017, Bobigny, France

Cécile Bichard, Nutroptimal, 1 Les Troques (Bâtiment LW1), F-69630, Chaponost, France

Frédéric Mistretta, RCTS, 38 Rue du Plat, F-69002, Lyon, France