Given that anyone can call themselves a nutritionist, how do you tell if a nutritionist's advice is worth heeding? How do you separate the quacks from the experts?

referrals, qualifications. ask them how they have helped others.

to be honest i dont see a lot of use in nutritionists except when it comes to people who have abnormal problems. You can learn what makes up a healthy diet, what to look for on packets, what to eat etc in a few hours if you arent a retard. I have occasionally given clients nutritional sessions and even gone with clients to the supermarket for a "supermarket safari" when they do their weekly shopping etc- and that is generally enough to put someones diet right. of course its up to them as to whether they actually eat what they are supposed to.

El macho is my nutritionist, he doesnt know it but he is. If I have a question I just do a lil searching, up a similar question pops and up pops an answer from macho. If that fails I just make a thread in which macho points me in the right direction or tells me straight out. I supplement my blind faith with nuts.