How can I make these statements natural?

Canada has many villages that I am thinking of visiting.
Generally, the islands* are underpopulated since they don't consist of much land for people to live on.
Canada consists of provinces and territories, whereas the USA consists of fifty states.
On the surface, our Bangladeshi culture looks similar to Indian culture.
Traditionally, Canadians have been far more emotionally reserved than Americans**.
Healthwise, Americans are very obese compared to their Canadian neighbors***.
There are certain searches that you have no choice but to consent to****. (comma removed)
India is one of the most overpopulated countries in the world.
It is said that businesses are there to meet the demands of their customers.
One of the major environmental problems, according to told by an Iranian man who has been living in Iran for a long time, is air pollution. (comma after major removed - major is clarifying the quality of the second adjective, "environmental", so it should not be separated by a comma).

* if you mean Canada's islands and are continuing the topic from the previous sentence. If not, then it is ok with a "the".

** This sentence is grammatically fine the way it is. But it suggests that that is about to change (Canadians are becoming less reserved than Americans). If this is not the case, then it is better to use the simple present tense - Traditionally, Canadians are far more emotionally reserved than Americans.

*** I would say "much more obese" instead of "very obese". With "very obese" you are not really making a comparison, you could simply say "Americans are very obese". But your sentence compares them to Canadians.

**** I'm not sure what you mean here. Like a security search (being "frisked") in an airport? In that case, it's ok, but the meaning does not come out directly.

Good job! :)