To lay to rest the notion that eating nuts leads to weight gain, researchers set out to determine how different daily serving sizes of pistachios affect body weight, blood pressure, blood lipids, blood glucose, and insulin. Subjects were randomized into groups that consumed either the recommended daily serving of pistachios (42g), a higher serving (70g, a little more than half a cup), or no pistachios at all for 12 weeks. The researchers saw no changes from baseline measurements. In fact, subjects who ate pistachios showed significantly lower blood glucose levels two hours after consuming 75g of glucose, indicating improved blood sugar regulation, and the group that ate the recommended daily serving of pistachios demonstrated considerably lower triglyceride levels, leading the researchers to conclude that daily nut consumption can actually reduce the risk of metabolic syndrome.
Reference: X. Wang et al., Nutr J., 11(1):20, 2012, Apr. 3. [Epub ahead of print.]