If imitation is the most sincere form of flattery, Subway and its young, folksy spokesman Jared Fogle must be overjoyed. The company's fast food rival Taco Bell has a new spokesmodel, Christine Dougherty, who purportedly lost 54 pounds over two years (results not typical) by eating from the chain's "Fresco" menu.

Bay area news radio station KCBS interviewed UC Berkeley nutrition specialist emeritus Joanne Ikeda to get her thoughts on Taco Bell's new advertising campaign. Ikeda said it's possible dieters could lose weight eating Taco Bell food, but not likely.

"If you make the right selections and...