@samgai It's really hard to make concrete, *because* it relies on social conventions - which are going to differ from place to place, and affect different people differently, so there's a good chance that any example I come up with doesn't resonate for you.

Nevertheless, as an example: there's a social convention in some places to only take a limited amount of food from the dinner pans at once, and 'not look greedy', on the premise that "you can always take more later if you're still hungry".

However, if you are unable to eat quickly due to disability, then there is a very high chance that the food will be gone before you get a chance to grab a second serving, even if you are still hungry.

You can't just take more - this will be considered greedy. Only eating one serving means you're still hungry. Asking for people to keep some apart for you not only would often be considered 'greedy' (because you are 'reserving' food), but also explicitly calls out the social convention of "appearing to take less by splitting up the servings".