Originally Posted by
ttama
And if the only choice was Prawn, which is a well-known allergen, how many passengers would have to reject it (or be forced to choose a special meal in advance)?
Prawn allergy affects much less than 1% of the population. The total food allergy rate in the UK is about 1.5%, for all foods, though for young children it is about 6% - they tend to grow out of it as their body develops. More people have some sort of food intolerance (e.g. coelic is about 1%, though only a quarter of that cohort will have a clinical diagnosis).