Airline food may get a bad rap for bland flavours and high calorie counts, but suggests that several carriers are bucking the trend with nutritious and environmentally friendly in-flight menus.

Air Canada and Alaskan Airlines shared the top spot in an annual ranking of 11 major carriers thanks to their healthy meals and their transparency concerning nutritional information.

Delta Air Lines and JetBlue Airways tied for second place. With a score of only 1.7 out of 5, Southwest Airlines earned the unenviable last-place finish.

, conducted by the Hunter College NYC Food Policy Center and DietDetective.com, ranked the airlines on the nutrients and calorie levels of meals, snack boxes, and individual snacks offered during their flights.

They were also scored on the improvement and maintenance of healthy offerings, the overall sodium levels in their food, water quality, and the availability of meals on flights that are under three hours long.

The airlines were also assessed on their level of transparency in terms of displaying nutritional information, and posting their menus and ingredients online.

To help travellers make the healthiest choices on their flights, the study also provides recommendations or 鈥渂est bets鈥 for what to order for each airline.

Air Canada:

With the introduction of several new items, such as the Grilled Chicken Summer Salad and Wild Rice Superfood Salad, Air Canada demonstrated some 鈥渟erious health innovation,鈥 according to the study. The airline also earned top marks for its 鈥渕ini meals,鈥 which are low in calories and high in nutrient content.

The company was chided, however, for not including all of its nutritional information and ingredients on its menu and online.

Best bets: The Liberte Greek yogurt, Avocado Smash Box (without the cheese), Grilled Chicken Summer Salad, and Wild Rice Superfood Salad.

Alaska Airlines:

Alaska Airlines ranked in the top spot with Air Canada because of its variety of snacks, snack boxes, and meal offerings with some 鈥渂etter-for-you鈥 options. The carrier was praised for its transparency compared to the competition and its environmental initiatives, including replacing plastic straws with paper ones and encouraging passengers to fill up water bottles before flights.

Best bets: Mediterranean Tapas snack box, Beef Jerky, Umpqua Oats Organic Apple Cranberry & Nut Oatmeal, Fall Harvest Salad, and Charge Up Protein Platter.

JetBlue Airways:

While JetBlue Airways was commended for posting all of its nutritional information online, the study said the data was not always up to date. As for its menu, the airline had a few 鈥渞easonably healthy鈥 meals and snack box choices, but they were only offered on longer flights.

JetBlue Airways was able to reduce the average number of calories in its food offerings from the year before, but the sodium content of all its food was higher than the average.

Best bets: The PickMeUp box, SavorUp box, FuelUp box, Fresh Fruit and the Jicama and Grape Salad Shake. As for complimentary snacks, choose anything other than the chocolate chip cookies.

Delta Airlines:

While the Delta Airlines鈥 collaboration with Luvo鈥檚 Performance Kitchen was applauded for its commitment to healthy eating, the airline was criticized for no longer offering those items as complimentary meals. The free meals were not as healthy, according to the study.

Like JetBlue Airways, Delta Airlines received points for lowering the average number of calories in its meals; however, the company had the highest sodium content of all the studied airlines.

Best bets: Almonds, Tapas Box, Protein Box, Sesame Noodle Salad, the Greek Mezze Plate, and the Performance Kitchen meals (if they鈥檙e available).

United Airlines:

The study said United Airlines was 鈥渋mproving鈥 and its average number of calories for all of its food items was 鈥渟ignificantly lower鈥 than the year before. The average sodium content was also lower than average.

The airline lost marks for not posting nutritional information on its website and lagging behind other carriers on environmental initiatives.

Best bets: Beef jerky, hummus, and pretzels (complimentary) for snacks. The Tapas snack box, Egg White & Chicken Sausage Flatbread Sandwich, and the Mezze Sampler are also good options.

American Airlines:

As the largest airline in the ranking, with more than 900 planes, American Airlines was criticized for not having more healthy food options. While the airline lowered the calorie count for a few of its menu items and received praise for its partnership with Zoe鈥檚 Kitchen, the company was slammed for its lack of variety and poor transparency on nutritional information.

鈥淧ringles are the only snack offered for purchase, not good. Come on, American鈥揾ealthy food is good business, have you heard of Whole Foods?鈥 the study said.

Best bets: The Continental Breakfast, Vegan Snack Box, Harissa Chicken Wrap, and the Hummus Duo (if shared or eaten as a meal). Avoid all the free or paid individual snacks.

Frontier Airlines:

The airline received a high rating for providing helpful information about its menu for the study, but it was criticized for its lack of healthy options, particularly for its snacks. The sodium content and average number of calories for Frontier Airlines鈥 snacks were much higher than the other airlines.

Best bets: The KIND bar, or Jack Links Beef Steak. Neither of the bundled snack boxes provides a nutrient-rich, low-calorie option.

Allegiant Air:

Like Frontier Airlines, Allegiant Air was also applauded for their cooperation in the study. However, the study said the carrier should offer a few more nutritious food items on its menu to receive a higher ranking.

Best bets: Nuts (if they鈥檙e shared), and the Hummus Snack Pack. Avoid the Deli Snack Pack and the Wingz Kids Snack Pack.

Spirit Airlines:

According to the study, there are 鈥渘ot many (if any) healthy options鈥 on Spirit Airlines鈥 menu. The average sodium content and calories for the airline鈥檚 snacks were well above the other airlines. They did, however, respond 鈥渋ncredibly well鈥 to the researchers鈥 questions.

Best bets: The FlyFit Protein Mix of nuts (if split among four people), Nissin Cup Noodle Very Veggie Chicken Flavor, and the Cheese Tray.

Hawaiian Airlines:

Hawaiian Airlines was criticized for being the only airline in the study to not provide complete nutrition information. The meals鈥 nutrient content was estimated by the research team鈥檚 registered dieticians because Hawaiian Airlines' information was 鈥渃onfusing.鈥

The study said the airline offers a lot of high-sodium and high-calorie options that are unhealthy.

Best bets: Kitchen & Love Quinoa with Artichoke and Roasted Pepper Quick Meal, the Gluten Free Box, and avoid all of the free meal 鈥渆xtras,鈥 such as chips, cookies, potato salad, and the pineapple coconut treat.

Southwest Airlines:

As one of the top carriers in the U.S., Southwest Airlines doesn鈥檛 offer much variety or nutritional value in its food offerings, the study said.

The airline received the lowest score out of all of the airlines in the study for its lack of healthy snacks. That is despite the fact the airline鈥檚 average calories for snacks decreased from the year before and the average sodium was also low.

鈥淢ore than on any other airline, when you fly Southwest, you need to bring your own fresh, nutrient-dense, healthy food, such as nuts and fresh fruit,鈥 the study said.

Best bets: Pretzels are the only 鈥渞easonable choice,鈥 but they don鈥檛 have any nutritional value, according to the study.