Body acceptance?

Obviously, it's important to love everyone regardless of what they look like. We should love and be kind to every race, every religion, every size, etc. BUT, here's my question. 
All of this "body acceptance", is it helpful? For people who are overweight, should we be telling them that their body is perfect the way it is even though their body is actually incredibly unhealthy? Is it more helpful and loving to encourage the person to get healthy, rather than encourage them to accept their body while it's sick and near death? 
This isn't at all meant to shame people and their bodies, I'm genuinely wondering what is more loving: encouraging one to get healthy, or encouraging one to settle for what they have?
(Yes, this is anonymous because I'm a chicken and you guys are sometimes scary.)