Tell me answer
Oh boy, not at all. Not all of them.
I have seen people cooking the same kind of food even after they have lived for more than 10 years in US or other countries in west. The only thing that changes is men from India starts to cook and help their better half more than what they used to when they were in India.
People who have migrated still worship their gods in their mandir(temple) at home.
They still go to temples close to their homes at least once in a month.
They still speak their native language at home. For example, in my case we want our kids to learn our Hindi language right from their formative years at home even though their first language is English. Not just that, with them we have been trying to learn Sanskrit just so that they understand that we are Hindus and we should be proud of our heritage. For some strange reasons, when we moved from Delhi to overseas in 2010, we never cared to learn a word of Sanskrit. It's only when you are outside your country that you understand the value of your culture in true sense.
They still celebrate all the Indian festivals whether they are in west or in east. It's so amazing that even when I was in China with my wife in 2010, we and many other Indian families were even doing karvachauth. Many people don't like to attend these festivities at temple but most of them still make sure they do it at their homes.
People still touch their elder’s feet(from India) even when they meet a random stranger here in US. I do it.
Now I understand, why people used to say when they used to come back to India after living overseas - ‘Saare Jahaan se acha, Hindustan hamara’. It is indeed true and a pat on the back of all the people living in west of Indian descent. Kudos to all of you for not losing your culture. Don't worry about what some people back home say that you have forgotten your culture. In the heart of your hearts you know what does it mean to be an Indian.
From a proud Indian, who loves his work and is passionate about his career wherever it takes me but still the heart is with India. Because there is still no country as good as India and absolutely no offense to any other country.