If you must choose between a trainer and nutritionist, step back and consider where you need the most help. Perhaps you're a real pro at the gym but clueless about whether to put butter or margarine on your toast. Or you've got your calories under control but find the weight machines a mystery. Whichever way you go, you'll maximize your investment by choosing a professional with good credentials and a stellar reputation. You'll score big if you find someone with extensive expertise in both areas; these days, more trainers are getting legit nutrition credentials and vice versa.

Stacy Berman, Trainer

If you are seeking professional help to reach your goals, the better buy would be a personal trainer. A trainer gives you motivation, knowledge and pushes harder than you would push yourself in a workout. Your trainer is there with you, making sure that you actually do what has to be done. A nutritionist only provides you with information, and you don't get the same hands-on experience that you would with a trainer.

Lisa Lillien, "Hungry Girl"

To me, this one is a no-brainer. Without a doubt, a personal trainer is a better buy. It would be nice to have a nutritionist personalize an eating plan tailored to you, but there is so much terrific nutrition info available online that any nutrition question can be answered almost instantly and for free. A personal trainer, on the other hand, can not only offer a tailored workout plan for you that can target specific areas of your body, but if you commit to weekly workout times and days, can actually force you to work out. I have had the same personal trainer for five years now, and it's because of him that I actually get my butt to the gym. (Thanks, Pete!) If you're really lucky, you may be able to find a personal trainer who is also a nutritionist.