We may be the world's most fervent barbecue devotees, along with Argentineans. In 1995 we seemed to favor both gas and charcoal equally, but since, the gas grills prevail in popularity.
Gas heats up so quickly with no mess, it's hard to argue with that.
As for healthy grilling, it makes no difference whether you use gas or charcoal. Fish, very lean meat and of course all vegetables are best. For example, grilled portobellos are used by many great chefs in lieu of meat. Grilling techniques can minimize risks and optimize flavor. Marinate 30 minutes only for fish or chicken, then discard marinade.