Mother insists that I should eat more vegetables.
The use of 食べろ makes me think mother is giving an order not a suggestion so, maybe
Mother insists that I have to eat more vegetables.
or
Mother requests/demands/orders that I eat more vegetables.
@mike-lima
This is another bad translation pair from Tanaka Corpus. The Japanese sentence, especially 要求する, sounds very unnatural. 食べろ isn’t a big deal here.
So, I suggest Clozemaster to revise the Japanese sentence and keep the original English sentence.
要求する means “to demand” or “to call for”. — e.g. “a kidnapper demands ransom”, “angry citizens call for the resignation of the mayor”. The Japanese sentence awkwardly means that “mother tried to get something from her child by forcing him to eat more vegetables.” It doesn’t make sense.
My alternative translations are:
お母さんは私に「もっと野菜を食べろ」と口うるさい。(くちうるさい)
お母さんは口を酸っぱくして私に「もっと野菜を食べなさい」と言ってくる。(くちをすっぱくして)
うるさい means “be noisy”, and 口うるさい means “the subject is so preachy that the listener is sick of listening to them”.
酸っぱい means “sour”, and 口を酸っぱくして is a frequent idiom meaning “to repeatedly give the same advice”. There are several theories behind its entomology such as “keeping talking makes one’s mouth full of acid saliva”.
食べろ and 食べなさい are interchangeable. They are used not only in an imperative sentence but in a “you should or had better do X” sentence. 食べろ in this context is most likely to be addressed to a male person (mother is talking to her son, not daughter), or the listener (mother’s child) is fed up with her advice.