Forget shakes, herbs, and high-tech energy boosters: The single best supplement for a guy's diet is a handful of nuts. Besides being known for helping fuel athletes through long days of climbing and skiing, nuts can help fight obesity and high blood pressure when added as a snack to a healthy diet. Recent studies have shown that nuts can decrease rates of heart disease and cancer and even extend life expectancy. But don't just reach for the peanut bowl: There's a science behind which nuts to eat and when to eat them.
Pistachios are particularly good for keeping your eyes healthy, thanks to significant amounts of the carotenoids lutein and zeaxanthin, which are stored in the retina and help maintain good vision.
When to grab a handful: Postworkout. Besides helping eyesight, pistachios are loaded with protein, which helps muscles recover. "An ounce has as much protein as an egg," says Upton.
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