This is a good question that I have asked before as well! Because of the pressure change when in the air, our body change as well. The food and the drinks will taste different. Have you tasted beer in the air? The taste of beer is totally weird and more bitter. So that's why one year ago the company I work for released its own brand of beer only for drinking in the air. It tastes sweeter than other beers. When I drink it at home, it is too sweet for me. I think maybe the air in the plane is too dry and hot then our sense of taste changes, so sweet drinks can make them feel good! Hope it can help you!