Example 1
During my trip in Japan, food was good; people were friendly.
Example 2
During my trip in Japan, the food was good; the people were friendly.
I feel like both actually mean the same. because with the context we can actually just pick up what food and people the speaker talking about without using a definite article.
Am I correct?
Omitting "the" is fine in a casual or spoken context. In a more formal written context, such as an essay, I'd prefer to include "the".
Without "the", it means "people in general were friendly (all across the world)" Of course, that's ridiculous, so the meaning will be understood. But I'd include the word "the" for correctness.
I'd also say "and..." since there are only two items in this list.
When speaking about what you had to eat while on vacation to a specific country, say, or at a new restaurant, it is idiomatic to refer to the food.
How was the food at that Mediterranean restaurant you went to?
This would be unidiomatic:
How was food at that Mediterranean restaurant you went to?
And when making a generalization about the citizenry of a particular place, again it is idiomatic to say the people but you have more freedom to drop the article:
How were the people there?
-- People seemed to be in a big hurry.
Both ways ultimately mean the same thing, but they create the meaning in different ways.
"The people" indicates a specific subset of people, while just "people" roughly means "some people" or "people in general".
In your story, "the people" means a specific subset of people, which is understood to be the people that you encountered on your trip to Japan.
Just "people" means people in general, without directly implying with the grammar that there's any subset, but because of the context of the story, it's still understood to mean the people that you encountered on your trip to Japan.
