I think it depends on the length of the flight, but should always be healthy and why not a bit of fun. If less than 2 hours of flight time having some fruit would be good and digestiv crackers. On a cross country flight something more substantial - cheese, crackers, fruit, nutrition bar, a salad with dried apples, quinoa/coucous, mixed greens. For oversees flights have to have a snack and a hot meal (why not include a soup) in a style that reflects the foods of the destination city.

I personally don't know.
I'm not sure respondents know
I'd construct a systematic design of basic food, preparation type, nature of serving
Populate it with 10 typles of food, 10 types of prepration, 10 types of serving
Do the study with 50 people, who will see cominations of food/prep type/serving ... and respond to the combinations
Within 10 minutes of the end of the study,you'll have your answer

hi
i would recommend small fruit salads, raw mixed nuts (unsalted), carrots/celery sticks.
i agree to do a consumer test with the right core target.

There are many limitations imposed on airline foods. These foods must be mass-produced to avoid additional preparation on the plane, usually frozen, low risk of food poisoning and cost-effective. I take a lot of flights and the best meals are simply foods that freeze well like curries, stews, casseroles. Sandwiches get slimy, pasta gets overly soft or dried out, meat and fish turn to rubber. In terms of side dishes, I agree with other respondents that fresh fruit would be nice.

https://www.inflightfeed.com/welcome-aboard/ and http://airlinemeals.net/ are really interesting websites discussing about this topic.
I would like to have helthy and nutritionally menu such as quinoa or salmon soy ginger or rice salads to have some examples, enough vitamin C too.

Healthier options on airlines should consist of lower sodium options on all flights. Additionally, alkaline water verses tap should be an option besides the sugary drinks and saccharin infused products that are being served. Foods with vitamin C and potassium would help inflight to help boost immunity. I realize that due to the influx of peanut allergies nuts have been discontinued in fights, which in my opinion is a shame. I don’t believe in soy products. As a health and wellness coach, I veer away from specific food groups. Anytime fruits, vegetables and legumes are added into the mix of foods it always becomes a healthier option.
The real issue in airline flights is the circulated forced air that causes people to get sick. Did you ever notice that when you are in first class you don’t get sick and in coach you do? Well it is because the airlines filter the vents in first class and don’t choose to in coach! For me the healthiest option is to regulate the air we breathe first and foremost and then look into what we consume.
Cheers!

Healthy food and drinks. More fruits, suggest small chuncs in a cup. Fresh vegetables, like in a mixed salad. Less sweets and food with saturated fat. Drinks with less sugar. No alcohol. Water for free.

If airline can always increase flight fare then the nature of flight meal should be at par with the fare. But more importantly, healthy and nutritional stuff should be served, I am yet to see fish (salmon) on any menu of airline passenger plane.

I agree with most of the other respondents. I'd love to enjoy a fruit and granola filled yogurt cup for breakfast flight, a healthy salad (with fish or chicken topping) for lunch. Not looking for heavy. Just satisfying and healthy.

For long haul, you could easily operate a menu based option. Premium choices can be selected and paid for prior to boarding. Everyone has a designated seat, so you can pack the trolly for optimal distribution on the ground. If you tie in the ordering system to online check in, you should be fine. (you have to do this to know seating & do your logistics prep)

Would be interesting to see an airliner try this on their Business Class and/or Premium Economy.

Water upon having settled, even before take off. Why do airlines serve drinks to business class passengers upon boarding, before take off, but to those in regular cabin, not until after take off? Offering water upon boarding would prevent dehydration. Fresh fruits, even a piece of banana would also be fine instead of the high sodium content pretzels and nuts.

This is really interesting for most of the passengers. However people from different geographical regions and different religion prefer to have food and snacks according to their choice and it sometimes might really be very difficult for airlines to meet the expectations of each and every passengers. For example, some passengers may prefer to have only halal and kosher certified food while some may prefer to eat only pure vegetarian. Some of the passengers eat only food without any onion, garlic, peanuts, etc. Some of them eat non vegetarian food but they eat only chicken and no fish or beef. These days, most of the people are preferring only healthy diet being more conscious about their health.
Hence in general the airlines should have a choice of all of these to fit in their short menu.

It would be better if airlines offered more food, snacks, drink selections on their flights. This would best accomplished via their website when booking the flight, then you can select your food, snack, drink choices to enjoy during the flight.

This could be included with your ticket/seat purchase or a separate fee. For example, you buy a coach ticket - you get to choose from a limited menu, you upgrade to first class or business class and you get more food, drink, snack items to choose from the menu.