DEAR DIANA

"Is first class worth it? People in the know, such as yourself, invariably recommend drinking lots of water in-flight, and light, healthy eating. Airlines recommend travelling in the luxury of business or first class where you pay exorbitantly for the privilege of eating heavy, unhealthy and alcoholic meals. Would a premium fare passenger stick to water and fruit, knowing that a large proportion of their fare is for the food/alcohol they are declining?" -Brian Philbey

DIANA RESPONDS

Many business travelers buy first class tickets because they write off the price of their tickets as a tax deduction. Some business travelers even claim that first class offers them opportunities to network with potentially lucrative business partners, buyers, sellers, and deal-makers, so extra air fare then adds up to more than just snob appeal. 

For me, the most significant first-class perk is oxygen. According to a study by the US National Academy of Sciences (The Airliner Cabin Environment, 1986), first-class passengers get about three times more oxygen per person than economy passengers!

First class is also about personal space. We have more leg room and more "pitch" room, i.e., we can recline our seats without feeling like we scrunch the person behind us.

The most obvious feature of first class is that there are fewer passengers, so we can usually get drinks more easily from flight attendants -- though I recommend getting up out of your seat anyway, just to get some exercise when you want a refreshment, and walking back to the galley. In first class, there's also less time waiting in line for a lavatory because there are fewer people.

As far as the much-advertised first-class free champagne, alcohol, unfortunately, is a diuretic and will exacerbate dehydration on long flights.