Nuts, especially almonds, are rich in monounsaturated fats, as are olive and canola oils.

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Rudel's monkeys benefited from these but not from the monounsaturated fats that the body can make itself.

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Liquid oils are usually unsaturated fats, including monounsaturated fats in olive and canola oils and polyunsaturated fats in safflower, corn, soybean and fish oils.

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Olive oil is composed predominantly of the monounsaturated fat oleic acid.

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Americans have spent the last few years mopping crusts of bread in extra virgin olive oil, proud to have replaced the saturated fats in butter with the supposedly healthier monounsaturated fats in olive oil.

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We do need some fat -- it transports fat-soluble vitamins (A, D, E, and K), carries flavors and helps you feel satisfied after eating -- but look for monounsaturated and omega-3 types and avoid saturated and trans fats.

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