Taco Bell’s “Fresco” menu items long ago joined the ranks of healthful fast-food options, which already included McDonald's limited-edition Go Active! Happy Meals for adults (complete with pedometer) and Pizza Hut’s “Fit N Delicious” line.

But now, the pseudo-Mexican fast food chain has a new infomercial starring a woman named Christine Dougherty, who says she lost 54 pounds on what the company calls the Drive-Thru Diet – a nickname for the seven items, including tacos and burritos, that the chain is offering, each with less than 9 grams of fat.

Christine’s story is a little skimpy on the details – she says in her statement and video that she reduced her total daily calorie intake by 500 calories to 1,250 calories by choosing Fresco items and “making other sensible choices.”How much of that was Fresco and how much was due to “sensible choices”? Let’s put it this way: The most notable difference between the regular and the Fresco tacos is replacement cheese with salsa. (For a little perspective, there are 100 calories in an ounce of Mexican-style shredded cheese, and about 10 calories for your typical salsa, according to this calorie calculator .)This doesn’t make for a huge caloric difference between the Fresco menu items and their “regular” counterparts. The Crunchy Taco Supreme is 200 calories; the Fresco version cuts that to 150. The Fresco burrito supreme with steak keeps it at 330 calories, while the normal version hits 380. That 50-calorie cut doesn’t even come close to cutting the 500 calories Christine said she dropped each day.I’m guessing “other sensible choices,” such as eating carrots as a snack or holding the whipped cream on that caramel macchiato, had much more to do with Christine’s weight loss than the type of tacos that she ate.Also? The blurb on Christine is more loaded with disclaimers than a box of cheese-covered nachos is with empty calories. The Drive-Thru Diet is “not a weight loss program,” Christine says, adding, “These results aren’t typical, but for me they were fantastic!” And in smaller print? Fresco is “not a low calorie food.”So Taco Bell makes no claims as to its tacos’ special weight-loss capabilities. And since many major fast food chains now offer healthful options, Christine could have just as easily credited McDonald's Southwest salad with chicken (320 calories) or Burger King’s veggie burger (420 calories). She could even have made that Subway sandwich a wrap to cut down on carbohydrates.When it comes to more health-conscious consumption, it doesn’t take a taco to start tracking your food’s energy content. Take a look at this counter the next time you want to evaluate how heavy your meal is.In any case, healthful eating should not be all about the calorie counting — consumers could theoretically cut their calories in half while on a steady diet of milkshakes and pizza. Maintaining a healthy diet also requires keeping track of those pesky vitamins and minerals, which come from a balanced intake of vegetables, fruits, nuts and other protein. Take a look at the USDA’s revised food pyramid for a better idea of what ingredients a good meal should include, whether it’s home cooked or passed through a drive-through window.

-- Amina Khan

Photo credit: Carolyn Cole / Los Angeles Times