This story is part of a series on finding the healthiest menu options at some of the most popular fast food restaurant chains.

(CNN) When you hear the name "McDonald's," a few things may come to mind: fast food, a Happy Meal, a Big Mac, Ronald McDonald or even shoestring fries. These days, though, the "M" that makes up the golden arches might as well stand for "menu changes."

The chain claims it's on a "food journey" and is committed to making changes that will make a positive difference for customers. As a result, McDonald's has made several modifications to its menu over the years. In the US, all Happy Meals now include either seasonal fruit (such as apple slices or an orange) or a low-fat dairy option. The Happy Meal still comes with fries, but you can opt for fruit or yogurt instead.

Other recent changes include baby kale, baby spinach, red leaf lettuce and ribbon-cut carrots to the chain's salad blends; milk from cows not treated with rBST, an artificial growth hormone; and chicken McNuggets with no artificial colors, flavors or preservatives.

McDonald's also offers a user-friendly nutrition calculator on its website that easily allows you to add and subtract meal components to see how, for example, small fries will impact the nutritional value of the meal (230 calories and 1.5 grams of saturated fat). Or how skipping Canadian bacon on an Egg McMuffin will impact a meal's overall sodium count (it will save you 200 milligrams).

Menu and website improvements aside, the chain's options are somewhat limited, particularly when you eliminate red and processed meats. That's why some of our favorite options are mentioned in more than one category. For example, when you have only two main salads to choose from, and one includes bacon, that doesn't leave you with many salad options. So you'll notice the Southwest chicken salad mentioned a few times, with slight variations. The same is true for the Egg McMuffin (now offered all day long) and the fruit and yogurt parfait: They consistently made the top of our list from a nutritional standpoint.

When choosing what to sip, steer clear of sugar-containing beverages (hot ones too), and opt for bottled water or a McCafé Latte with nonfat milk. And when it comes to shakes, don't be fooled by "small" sizes: A small strawberry shake will cost you 74 grams of sugar, or 18.5 teaspoons. That's three times the daily sugar recommendation for women and two times the limit for men.

Below are the best McDonald's options if you're focused on healthy choices within the limits of the menu. We break it down by our picks for kids, athletes, drivers, vegetarians and vegans, as well as low calorie, low sugar, low salt, gluten-free and low-carb options.

For kids

Our picks: Happy Meal with chicken McNuggets (4 pieces) with honey mustard dipping sauce, apple slices, Yoplait Go-gurt low-fat strawberry yogurt and low-fat (1%) milk jug

When it comes to kids' meals, you really can't go wrong by choosing a Happy Meal with chicken McNuggets (four pieces), apple slices, a low-fat yogurt stick and low-fat milk. The chain also offers a Mighty Kid's Meal, which includes six chicken McNuggets, for bigger appetites.

The apples and the yogurt stick are a welcome substitution for fries and nicely balance out the meal. However, if your child insists on having fries, it's probably not worth the fight: An order of kids' fries has only 110 calories and 1 gram of saturated fat, thanks to its smaller size.

The same thinking applies to the soft-serve ice cream cone, which provides only 45 calories (yes, that's correct) and 6 grams of sugar. No need to sweat this sweet.

For vegetarians

Our picks: Fruit and yogurt parfait (snack/mini meal); or Southwest salad (no chicken) with Newman's Own creamy Southwest dressing

We love McDonald's fruit and yogurt parfait, a mix of low-fat yogurt with strawberries, blueberries and crunchy granola. It's tasty, low in saturated fat and calcium-rich and offers berry antioxidants -- and therefore a no-brainer for vegetarians. It is on the lighter side, though, so we consider it more of a mini-meal or snack, unless you pair it with a side salad.

We also really like the Southwest salad, sans chicken. It offers 8 grams of protein, partly from the shredded cheese, and 6 grams of filling fiber. And it's loaded with flavor, thanks to the cilantro lime glaze and vegetable blend, a mix of black beans, roasted corn, tomatoes and poblano peppers.

For vegans

Our picks: Southwest salad (no chicken or cheese) with Newman's Own low-fat balsamic vinaigrette; or side salad with balsamic vinaigrette and hamburger bun; and a "Cutie" (mandarin orange)

There's not a lot to choose from at McDonald's if you are vegan; even the French fries contain beef flavoring. Your best bet is the Southwest salad without chicken or cheese. The vegetable blend, containing corn, black beans, tomatoes and poblano peppers, will give you a fiber boost, and the tortilla chips offer a bit of crunch.

You can also opt for a side salad and hamburger bun and create what we would consider to be a McDonald's "veggie burger." The chain doesn't offer a traditional one. We recommend the low-fat balsamic dressing.

Add a "Cutie" (mandarin orange) to either option for a vitamin C boost.

For calorie counters

Our picks: Southwest grilled chicken salad (without dressing); or bacon ranch grilled chicken salad (without bacon and with half a packet of Newman's Own ranch dressing); or Egg McMuffin (without Canadian bacon or butter); and fruit and yogurt parfait (snack/mini meal size)

Even when you are counting calories, it's smart to look at everything a food offers, because lower-calorie foods are not necessarily the healthiest -- or the most filling. For example, a McDonald's hamburger is only 250 calories, but it's a source of red meat, which we recommend consuming only in moderation. And although a four-piece chicken McNuggets has only 180 calories, it may leave you feeling a bit hungry.

Our favorite low-cal pick on McDonald's menu is the Southwest grilled chicken salad, with 350 calories. It's filled with flavor and crunch, thanks to roasted corn and tomatoes, black beans, a cilantro lime glaze and chili lime tortilla strips. And with 37 grams of protein, it will keep you sated until your next meal. We recommend skipping the dressing, which adds 120 calories. You won't miss it.

If you want a simple grilled chicken salad with tomatoes and shredded cheese, order the bacon ranch grilled chicken salad, and omit the bacon. It may sound silly, but it will lower the calories (from 320 to 230) and sodium (from 1,090 milligrams to 730 milligrams). We also recommend using only half the packet of ranch dressing, which brings the salad total to 330 calories.

The Egg McMuffin has only 250 calories if you go without Canadian bacon or butter. And it's now offered on McDonald's all-day breakfast menu. If you're looking for more of a snack or mini-meal, the fruit and yogurt parfait is a satisfying low-cal option.

For the sugar-sensitive

Our picks: Chicken McNuggets (six pieces) with spicy buffalo dipping sauce; or Egg McMuffin (without Canadian bacon or butter)

The lowest-sugar option on McDonald's menu is an order of chicken McNuggets, with zero grams of sugar, whether you opt for a four-, six- or 10-piece serving. Adding the spicy buffalo dipping sauce, made with cayenne pepper, won't contribute any sugar grams either (definitely a pleasant surprise). But steer clear of the tangy barbeque and sweet 'n' sour and sauces, as well as the honey, which contribute 9, 10 and 11 grams of sugar, respectively.

Another low-sugar option is the Egg McMuffin. It has only 2 grams of sugar, or just half a teaspoon. We recommend skipping the Canadian bacon and butter to save on saturated fat and sodium.

For the salt-sensitive

Our picks: Filet-o-fish (without tartar sauce or cheese); or side salad with Newman's Own creamy Southwest dressing (half a packet); and mandarin orange or yogurt parfait

If you're watching sodium levels in foods, it's smart to keep a close eye on condiments. For example, removing the tartar sauce and cheese from the Filet-o-fish sandwich lowers the sodium count to 360 milligrams, from 570 milligrams, and makes it one of the lowest-sodium sandwiches on McDonald's menu.

If you choose McDonald's hamburger and eliminate the ketchup, pickles, onions and mustard, you'll get the same sodium count.

Adding a mandarin orange "Cutie" gives a potassium boost, which can help lessen the effects of sodium on blood pressure.

Another lower-sodium option is the side salad with a fruit and yogurt parfait. The salad has only 15 milligrams of sodium, but selecting dressings is the challenging part. The dressing that adds the least amount of sodium is Newman's Own creamy Southwest dressing. The whole packet has 300 milligrams of sodium; we recommend using half, bringing the salad total to 165 milligrams. Pair it with the fruit and yogurt parfait, which offers a helpful dose of potassium and calcium.

For the gluten-sensitive

Our picks: Southwest grilled chicken salad (without dressing or tortilla strips); or Egg McMuffin (without muffin and butter)

According to McDonald's website, the chain does not certify any menu items as gluten-free and encourages customers to check ingredient information for individual items. And like other chains, it cautions that there is potential for cross-contamination among non-gluten-containing foods. So we wouldn't recommend a visit to Mickey D's if you have celiac disease.

But if you are looking to avoid gluten for other reasons, we recommend the Southwest grilled chicken salad, minus the tortilla strips (though they're made with corn, the chain cautions that it would not certify the tortilla strips as gluten-free). You won't be deprived of flavor if you skip the dressing, as the salad comes with a tasty vegetable blend and cilantro lime glaze. But you will save on sodium and calories, which is helpful when you consider a total day's intake. If you still prefer dressing with your salad, use only half a packet.

If you are a gluten-free egg lover, take advantage of the chain's all-day breakfast menu and go for a muffin-less Egg McMuffin (it may sound strange, but we can tell you it's been done before). You'll enjoy eggs, Canadian bacon and cheese without the gluten. We recommend skipping the butter, too.

For the athlete

Our picks: Artisan grilled chicken sandwich; or fruit and maple oatmeal without brown sugar; and fat-free chocolate milk jug

Whether you favor cardio or weights, McDonald's artisan grilled chicken sandwich will satisfy your nutritional needs for workouts. It offers 44 grams of carbs to fuel muscles and maintain blood glucose levels during exercise, and it has 37 grams of protein for muscle building and repair. It also delivers a healthy dose of iron, which is especially helpful for endurance athletes.

The chain's fruit and maple oatmeal without brown sugar is also rich in carbs and ideal before a morning cardio workout.

When it comes to post-workout beverages, McDonald's fat-free chocolate milk jug offers 23 grams of carbs and 9 grams of protein -- a favorable ratio for muscle repair and recovery.

For the road warrior

Our picks: Filet-o-fish (without tartar sauce); or artisan grilled chicken sandwich; and apple slices

When you're on the road, a sandwich is a quick and easy grab-and-go option. One of our favorites at McDonald's is the Filet-o-fish sandwich, made with omega-3-rich pollock. The tartar sauce doesn't make a huge dent in your daily saturated fat budget at only 1.5 grams, but skipping creamy sauces is a good habit, especially if you're watching calories, too.

We also like the artisan grilled chicken sandwich, with 37 grams of protein and only 2 grams of saturated fat. It will be sure to prevent hunger pangs during your travels. Grab some apple slices to have handy in case your trip ends up taking longer than planned.

For the carb-conscious

Our picks: Artisan grilled chicken sandwich (without bun); or Egg McMuffin (without muffin and butter); or cheeseburger (without bun); side salad with Newman's Own low-fat balsamic vinaigrette

Ordering the grilled chicken sandwich and tossing the bun brings the carb count of this sandwich down from 44 grams to only 2 grams. Bypassing the bun also slashes 350 milligrams of sodium.

Low-carb dieters may also enjoy the Egg McMuffin without the muffin and butter, which has only 3 grams of carbs. If you are craving a burger, we recommend a bunless cheeseburger, with only 5 grams of carbs. It also won't drive sodium or saturated fat levels through the roof. Plus, the cheese offers a calcium boost.

For some greens, choose a side salad with balsamic vinaigrette dressing, which adds only 8 grams of carbs to the meal.

For the breakfast lover

Our picks: Egg White Delight McMuffin (without Canadian bacon or butter); or fruit and maple oatmeal without brown sugar

There's not a whole lot of healthiness to choose from on McDonald's breakfast menu, once you eliminate bacon- and sausage-containing sandwiches. Then again, it just takes one, and the chain's Egg White Delight McMuffin is a healthy, protein and calcium-rich option. The Canadian bacon that it comes with contributes only 20 calories, but it also delivers 200 milligrams of sodium, so we recommend skipping it and ordering it without butter too.

Join the conversation See the latest news and share your comments with CNN Health on Facebook and Twitter.

If you prefer more carbs in the morning, we really like the chain's fruit and maple oatmeal without brown sugar but with diced apples, cranberries and raisins. It doesn't have as much protein as the egg sandwich, but it does offer 5 grams of fiber and is particularly beneficial if your morning routine involves a lot of walking.

Note that the oatmeal is available on the chain's all-day breakfast menu. We wish the same were true for the Egg White Delight, but according to a company representative, "Upon request, our restaurants would prepare an Egg White Delight for our customers. It's just not part of the national advertising."