Regarding R’ Moshe on smoking:
Igros Moshe Yoreh Deiah 2:49
http://hebrewbooks.org/pdfpager.aspx?req=919&pgnum=67
Igros Moshe Choshen Mishpat 2:76
http://hebrewbooks.org/pdfpager.aspx?req=921&pgnum=315
In the second one he also talks about eating unhealthy foods.