They aren't!

You are typically going to be sitting down and getting very limited exercise. On a long haul flight of 12 hours, based on a 2000 kcal/day requirement, the average person will burn in and around 1000 calories.

A conservative estimate for the calories in that small breakfast picture would be around 300, and that's a New York to London flight, which is in the 6-7 hour (i.e. 500-600 calorie) range.

Add to that calories from drinks and snacks and I'd suspect that the typical passenger over-consumes on a long-haul flight.

They aren't!

You are typically going to be sitting down and getting very limited exercise. On a long haul flight of 12 hours, based on a 2000 kcal/day requirement, the average person will burn in and around 1000 calories.

A conservative estimate for the calories in that small breakfast picture would be around 300, and that's a New York to London flight, which is in the 6-7 hour (i.e. 500-600 calorie) range, and on which another, more substantial, meal is also served not long after takeoff.

Add to that calories from drinks and snacks and I'd suspect that the typical passenger over-consumes on a long-haul flight.