These days fast food chains are spending big marketing dollars on trying to convince consumers they've got healthier, fresher options.

Subway has long been marketing its "Eat Fresh" tagline (and who could forget the "$5 footlong"?), but even it had a simpler message in its early days. Take this Subway ad, one of the chain's first. In case it's not clear from the fashion choices and the actress with the Dorothy Hamill haircut, this spot is from 1977.

The chain's plea to consumers is uncomplicated: when you're hungry, get to a Subway restaurant as fast as your legs can carry you.

Although the hunger message is the main point of the TV spot, notice that the voiceover makes a passing reference to freshness and customization -- two points that Subway to this day still uses as a key part of its marketing strategy. "Subway's famous, giant footlong sandwiches are made right before your eyes, the way you want them," says the ad copy. "A variety of fresh and delicious ingredients. If you're really hungry, nothing beats a Subway."

The jingle, which has a Three Dog Night quality to it, is titled "Make Tracks for Subway" and was written and recorded by Don Fertman --the chain's now chief development officer -- and his band, The Crayons.

Mr. Fertman didn't start working for Subway until 1981, when the chain had just 166 locations, a fraction of its global presence today.

"I've worn many hats while working for Subway over the years, and it's been incredible to watch this small sandwich chain grow to nearly 40,000 locations in 102 countries," said Mr. Fertman. "Today, Subway is a global brand that speaks to fans daily across channels we couldn't even dream of when my band wrote its first jingle for the company."

Subway throughout the 1980s and 1990s expanded at an impressive clip and is now the second-largest fast-food advertiser in the U.S. behind McDonald's. Not bad for a chain started in 1965 in Bridgeport, Conn., by Fred Deluca, who opened the shop to help pay for his medical-school education.