paheli type sms

I am a word of five letters!
People eat me!
If you remove my 1 letter i will be a form
Of energy!
If you remove my first 2 letters i will be needed 4 living.
If you remove my first 3 letters i will be near you.
If you remove my first 4 letters i will be a drink 4 you.
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Who am i?
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Answer is : wheat