Nutritionist for teen athlete

My 17-yr old son has recently become very devoted to working out and feels great. But he's struggling to find good advice about nutrition for active teens who are interested in building muscle mass. Much of the advice he's found seems extreme (e.g., very high protein, super rigid eating routines, never eat certain foods). He'd like to meet with someone knowledgeable in the area of adolescent nutrition for athletes. We've got good insurance (it would be great if a consultation of this sort were covered) but, if not, we'd be willing to pay out of pocket if he walked away with good, balanced information. Anyone know someone who might fit the bill?