Cashews
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Cashews are a good source of magnesium, a mineral in which most Americans are deficient. Magnesium helps improve blood-sugar sensitivity and can limit weight gain. Most of the unsaturated fat in cashews is a type known as oleic acid, the same variety found in olive oil, which studies show may help reduce heart-disease risk. 

How to eat them: Soak cashews in a bowl of water for two hours. Blend with water for a cream substitute in soups.