Nuts are nature's way of showing us that good things come in small packages. These bite-size nutritional powerhouses are packed with heart-healthy fats, protein, vitamins, and minerals.

Here's a look at the pros and cons of different nuts, as well as the best and worst products on supermarket shelves today. Of course, you can get too much of these good things: Nuts are high in fat and calories, so while a handful can hold you over until dinner, a few more handfuls can ruin your appetite altogether. And although nuts are a healthy choice by themselves, they'll quickly become detrimental to any diet when paired with sugary or salty toppings or mixes.

Best nuts for your diet:  Almonds, Cashews, Pistachios

All nuts are about equal in terms of calories per ounce, and in moderation, are all healthy additions to any diet. Their mix of omega-3 fatty acids, protein, and fiber will help you feel full and suppress your appetite.

The lowest-calorie nuts at 160 per ounce are almonds (23 nuts; 6 grams protein, 14 grams fat); cashews (16 to 18 nuts; 5 grams protein, 13 grams fat); and pistachios (49 nuts; 6 grams protein, 13 grams fat). Avoid nuts packaged or roasted in oil; instead, eat them raw or dry roasted. (Roasted nuts may have been heated in hydrogenated or omega-6 unhealthy fats, or to high temperatures that can destroy their nutrients.)

Worst nuts for your diet:  Macadamia Nuts, Pecans

Ounce for ounce, macadamia nuts (10 to 12 nuts; 2 grams protein, 21 grams fat) and pecans (18 to 20 halves; 3 grams protein, 20 grams fat) have the most calories— — 200 each— — along with the lowest amounts of protein and the highest amounts of fats.

However, they're still good nuts: The difference between these and the lowest calorie nuts is only 40 calories an ounce. As long as you're practicing proper portion control and not downing handfuls at a time, any kind of raw, plain nut will give you a good dose of healthy fats and nutrients.

Best nuts for your heart:  Walnuts

While all nuts contain heart-healthy omega-3 fats, walnuts (14 halves contain 185 calories, 18 grams fat, 4 grams protein) have high amounts of alpha linoleic acid (ALA). Research has suggested that ALA may help heart arrhythmias, and a 2006 Spanish study suggested that walnuts were as effective as olive oil at reducing inflammation and oxidation in the arteries after eating a fatty meal. The authors of this study, funded in part by the California Walnut Commission, recommended eating around eight walnuts a day to achieve similar benefits.

Best nuts for men:  Brazil Nuts, Pecans

Creamy Brazil nuts are packed with selenium, a mineral that may protect against prostate cancer and other diseases. Just one nut contains more than a day's worth, so eat these sparingly: Recent research has hinted that too much selenium may be linked to type 2 diabetes risk. One ounce of Brazil nuts (6 nuts) contains about 190 calories, 19 grams fat, and 4 grams protein.

Pecans are also good for men's health: They're loaded with beta-sitosterol, a plant steroid that may help relieve symptoms of benign prostatic hyperplasia (BPH), or enlarged prostate. One ounce of pecans (18 to 20 halves) contains about 200 calories, 21 grams fat, and 3 grams protein.

Best nuts for disease prevention:  Almonds
Relatively low in calories, almonds have more calcium than any other nut, making them a great food for overall health. Plus, they are rich in fiber and vitamin E, an antioxidant that helps fight dangerous inflammation and possibly health conditions such as lung cancer and age-related cognitive decline.

Because they're so versatile, almonds are often a favorite among nut eaters: You can buy them raw, toasted, slivered, or coated with a variety of fun flavors, from Wasabi & Soy Sauce to Lime 'n Chili.

Best snack packaging for nuts:  Choose 100- to 200-calorie packs

Because nuts are so high in calories (and so tasty, to boot!), it's important to practice portion control when eating them as a snack. 

Worst snack packaging for nuts:  Avoid anything in a tub

We're all for buying in bulk to save money and packaging, but it's important not to snack straight from the box (or in this case, the giant tub) when a craving hits. 

The Party Mix variety also like M&Ms and sugary yogurt-covered raisins, for an extra calorie boost. 

Best nuts for chocolate lovers: Go for cocoa-dusted almonds

Rather than hiding your nuts under a thick layer of sugary chocolate candy— — think peanut M&Ms— — keep it simple like Cocoa Roast Almonds. 

I'd give you a "worst" nuts for chocolate lovers, but the possibilities are practically endless. Just think of it this way, Anything that's more chocolate than nut really should be considered candy — —not as a way to get your daily quota of healthy fats.

Best nuts for your sweet tooth: Try all-natural glazed nuts

Want something sweet and satisfying but without the extra calories and high-fructose corn syrup? Look no further than glazed nuts, try and find something that is sweetened with organic cane juice or something similar. 

Worst nuts for your sweet tooth:  Check labels for sugar content

Just because something has nuts in it doesn't make it good for you "Don't justify eating a Snickers because it's got peanuts in it." Anything coated with or tucked inside layers of sugar, toffee, chocolate, or ice cream isn't going to give you much nutritional benefit, and the calories can quickly add up.

Best nuts for a salt craving:  Look for 'lightly salted'

If you don't have high blood pressure or haven't been warned away from salt by your doctor for other reasons, a handful or two of salted nuts a day won't hurt you.

Nuts are, of course, available unsalted. But to satisfy a salty craving without going overboard, look for in-between varieties like lightly Salted peanuts, almonds, and cashews, or Pistachios Lightly Salted. Check ingredient labels, too: Some brands contain less salt than others.

Best trail mix:  Raw nuts, seeds, and dried fruit

Trail mix is available in countless varieties and from countless brands. "Look for trail mix with raw nuts,Or if the nuts are roasted, look for the words 'dry roasted' rather than 'oil roasted.'"

Nuts pair great with fruit, seeds, and perhaps even a little dark chocolate, just pay attention to the calorie count and serving size. 

Worst trail mix:  Save high-calorie mixes for the trail

High-calorie trail mix is fine when you've got a long hike ahead of you, but too often we eat these store-bought blends while sitting at our desks or driving in our cars.

Also check labels for sky-high sugar contents: Some trail mixes— — especially those with raisins, dried cranberries, and/or candy-covered chocolate pieces— — can contain up to 18 grams of sugar per serving.

Best nut butter:  Keep ingredients simple

When choosing a nut butter, look for spreads with the fewest ingredients possible: Just nuts (and salt, if you want). Keep natural peanut butter in the fridge to keep it from going rancid and to prevent oily separation.

Worst nut butter:  Skip added oils and sugars

Major brands have eliminated trans fats from their nut butters, but most still contain hydrogenated oils (high in saturated fat) to increase spreadability and prevent separation. Some "natural" product lines swap hydrogenated oils for palm oil, also high in saturated fat. Skippy Natural with Honey, for example, contains 200 calories, 16 grams fat (3.5 grams saturated), and 5 grams sugar per 2-tablespoon serving.

Nutella's creamy chocolate-hazelnut combo is terrific for an occasional treat — —but it's hardly part of a "balanced breakfast," as its commercials say. Two tablespoons contain just 200 calories, yes, but 21 grams of sugar. In fact, sugar and palm oil are the product's first ingredients, even before hazelnuts.

Best way to eat nuts: Pair them with a healthy carb

Now you know all about which nuts are good for what — —but to get the most health benefits, it's also important to pay attention to how you eat them. "Nuts are a great thing to eat when you're having a carbohydrate like fruit or juice, because it helps slow down digestion and the breakdown of sugar," 

Best nuts overall:  A mixed bag!

So which is the healthiest nut overall? Mixed nuts, ideally raw and unsalted, provide the best variety of nutrients and antioxidants.