I'd also like to know how to politely ask for more food.

我还想知道怎样有礼貌地要更多的食物。

youdao

After a long discussion, they decided that one of them should ask for more food after supper that evening, and Oliver was chosen.

经过长时间的商量，他们决定必须有一个人在当天晚饭后，去请求多给点吃的。结果，奥利弗被选中了。

youdao

While eating, the elders will use chopsticks to pick up food for guests as a tradition and ask them to eat more.

吃饭的时候，按照传统，长辈们会用筷子夹食物给客人，并让他们多吃点。

youdao

She is expected to ask for more visas for foreign aid workers as the Syrian Arab Red Crescent struggles to distribute food.

BBC: Syria crisis: China hosts Assad aide Bouthaina Shaaban

Still, greater awareness of food allergies has come as restaurant diners ask for lists of ingredients in meals and preparations and more people know someone with another type of food intolerance such as gluten sensitivity.

WSJ: Finding Food Allergy Allies