Since the tenderloin is simply part of the breast, I just use something like "Chicken breast, boneless, raw, yield after skin removed" (can't get the link to work!). Anyway, as long as the calories are the same as what's on the package (about 25 calories per ounce), I tend not to get too freaked out about the particulars. This is one of those foods where you can easily get good at eyeballing portion sizes. Each one of those "fingers" is about 2-3 ounces (the way I buy them), so two makes a good main course for me. I love cooking with these things; they're cheaper, they thaw from the freezer in no time, and they are more tender than the rest of the breast.
One delicious way I've been eating them is with a terragon mustard sauce. I discovered the recipe from Martha Stewart of all places! Cook the tenderloins in a skillet with a little bit of olive oil, remove them and pour about 1/2 cup of white wine or chicken broth into the hot pan. Whisk up all the "bits" leftover from the chicken. Wait until it reduces a bit, whisk in a dollop of half and half (Martha's recipe, of course, uses a lot more) and a tablespoon or two of Dijon mustard. Keep whisking and add a little bit of fresh terragon (thyme is also good). Drizzle the sauce over the chicken, serve with asparagus or greens and a piece of fruit and you're good to go!
Hope that helps!