The good news is that nearly all nuts are good for you, but some are better than others because they provide higher amounts of protein or nutrients that have health benefits. As a rule, about one ounce, or 1/4 cup, is a typical portion of nuts. Portion size is important because while nuts offer healthy benefits, they also contain higher amounts of fat.
Walnuts are number one of the healthiest nuts because they're the only nut to offer plant-based omega-3 fatty acids. According to the American Heart Association, omega-3 fats may help lower cholesterol levels and support a healthy heart, and they also help brain function. A single serving of walnuts provides 185 calories, 4 grams of protein and almost 2 grams of fiber.
Almonds are loaded with key vitamins and minerals. A single serving of almonds provides enough Vitamin E to equal up to 35 percent of the recommended daily intake. Almonds also contain calcium and folate, some of the nutrients lacking in the typical American diet, according to the Dietary Guidelines for Americans 2010. Almonds also have the highest protein per serving among nuts: a whopping 6 grams per ounce.
Pistachios boast a larger serving size versus other nuts, and they also provide the highest fiber content (about 3 grams per serving) and nearly 6 grams of protein per ounce. Pistachios might help control hunger because of their high protein and fiber.
Less-healthy nut choices . . .
Macadamia nuts are delicious but contain the most fat per serving — 17 to 22 grams and 204 calories per ounce — making them a higher calorie choice than most nuts. Macadamia nuts are relatively low in protein compared to other nuts, with less than 2.5 grams per one-ounce serving. While Macadamia nuts aren't all bad since they offer a good dose of healthy fat, they're a poorer nut choice.
Source: Good Nuts vs. Bad Nuts by Lindsay Stern, MPH, RDN, LN