Nuts For Health

(CBS)  If you're looking for the perfect diet, you have to be crazy if you don't include nuts.

The Early Show Medical Correspondent Dr. Emily Senay tells how to sort through the mixed nut selection to pick the healthy ones.

Nuts are part of the meat group in the food pyramid because they are a good source of protein. They also contain lots of fiber, lots of vitamins and other nutrients. Nuts were not always seen as a health food because they are high in fat, but now it is understood the types of fat they contain are, for the most part, quite healthy.

Nuts are cholesterol-free and contain mostly mono- and polyunsaturated fats, the so-called good fats, as well as the beneficial omega-3 fatty acid like that found in fish.

Senay says the following nuts offer the most benefits:

Almonds (164 calories, 14.4 g fat per ounce)

Peanuts (160 calories, 14 g fat per ounce)

Pistachios (158 calories, 12.6 g fat per ounce)

Studies looking at almonds, peanuts, pistachio nuts have shown that people who regularly eat these nuts have lower cholesterol levels. Senay says they are all really good sources of protein and fiber. Almonds are also a good source of vitamin E, magnesium and calcium. Peanuts are high in folate and iron. Pistachios are a great source of potassium.

Senay says too much salt can increase blood pressure, so you should take that into account when you eat nuts. But there is no difference between the nutritional make-up of raw nuts compared to dry roasted nuts. Oil-roasted nuts have slightly more fat and calories.

Some nuts do contain more fat than others. Senay lists the following that are high in fat:

Walnuts (185 calories, 18.5 g fat per ounce)

Hazelnuts (178 calories, 17.2 g fat per ounce)

Cashews (160 calories, 13.3 g fat per once)

Walnuts are higher in fat, but they are particularly high in Omega-3 fatty acids, the type of fat that is helpful for fighting disease. An ounce and a half of walnuts -- a handful or two -- fulfills the daily requirement of these fats. Hazelnuts are also higher in good monounsaturated fat, and have a lot of vitamin E and iron. Cashews have more saturated fat, but are a great source of copper, magnesium and iron.

Senay says eating one to one and a half ounces of nuts (about the size of a small handful) is appropriate for most people, but it also depends on the type of nuts.

Brazil Nuts (186 calories, 18.8 g fat per ounce)

Pecans (196 calories, 20.4 g fat per ounce)

Brazil nuts are high in magnesium and the antioxidant selenium, but they're higher is saturated fat. Too much selenium can cause health problems, so Brazil nuts are not recommended in large amounts. Pecans are a good way to get copper and zinc, but are also higher in fat content.

Senay says there are also nuts that don't contribute much to a balanced diet. She list the following as examples:

Chestnuts (69 calories, .6 g fat per ounce)

Macadamia Nuts (204 calories, 21.5 g fat per ounce)

Chestnuts are really low in fat and calories, but also in heart-healthy benefits. Macadamia nuts are the opposite. They are high in plant sterols that lower cholesterol, but also very high in fat and calories.