That's a matter for much debate. Most people that go with a body lift later regret it and wish they had just gone with a suspension lift. Honestly I can't see how doing a body lift would cause any problems, and IMO a quality suspension lift is just as good or better then stock components. The issue I think that comes up is that people that do a lift tend to get bigger tires, that causes more wear on transmissions and axles and other drivetrain components. They also start to wheel more often, that causes the most damage. About the worse thing for a truck is to wheel it, yet it's also some of the most fun you can have. Funny how that works out.
Just my $0.02, I have no valid data other than my opinion to back that up.