LOS ANGELES (CNN) -- The hot food item for the late 90s may not be food, well, at least not plain old food.

Sports energy bars, pocket-sized packaged food bars, often loaded with protein, vitamins, minerals and lots of carbohydrates, are showing up in plenty of places outside of the gym.

"The market has expanded so rapidly because of the changing lifestyles of consumers," said Jim Wolfe, CEO of Balance Bar Company. "They are skipping meals.They don't have time to eat three meals a day, so the nutrition bar format is ideal for consumers."

Wolfe said sales of his company's Balance Bars soared from $1 million dollars in 1995 to $40 million dollars last year.

Booming sales may be helped by the fact that some Hollywood stars make energy bars part of their exercise routine.

"We were smuggling them into Argentina when we were shooting "Evita," said Madonna's personal trainer, Ray Kybartas. "We kind of camoflauged them as books."

Energy bars come in a variety of flavors and many follow the so-called 40/30/30 formula, or 40 percent carbohydrates, 30 percent protein and 30 percent dietary fat.

While the sugar in the sports bars may make you feel energized, it's better to get nutrition from plain old-fashioned food, said some health experts.

"When people forgo conventional meals for the use of a sports bar, they are not getting [adequate] nutrition," said sports nutritionist Ellen Coleman.

Sports bars can also be very dry.

"They don't tend to have any water in then and you must drink a considerable amount of water to keep everything going," said Dr. Samuel Bessman.

Bessman, a pharmacology professor and expert on the way the human body metabolizes food, said he isn't against sports bars, but he doesn't believe they offer anything special.

CNN Correspondent Charles Feldman contributed to this report.