If anyone wanted to see an exception to the "form follows function" design rule, the first generation of fanny packs should fit the fill. The original waist pack was a reinforced nylon zippered pouch which attached to the user's waist with an adjustable belt and clip. A waist pack or fanny pack was designed to hold essential items such as keys, cellphones, water bottles, medicine or food items while the user pursued activities such as hiking, biking or walking.
The problem with the original generation of fanny packs or waist packs was more of a question of aesthetics rather than pure function. As these strap-on pouches became more and more popular among tourists and other non-outdoor enthusiast types, the mere sight of a bulging fanny pack worn prominently on the user's lower abdomen or waist became a little troublesome. Although few people actually kept their fanny packs slung across their actual fannies for security and comfort reasons, the original waist pack or fanny pack did not exactly catch on as a fashion accessory.
Even as the original generation of waist pack began to fade into fashion obscurity, several sporting goods companies began reworking the basic idea into a more functional and in some ways more fashionable piece of real sporting and camping equipment. Users could now fit an entire water bottle into a separate holder, for instance.
Other improvements to the original fanny pack concept include additional zippered compartments for cellphones, climbing equipment, chalk bags, food and other necessities. A modern waist pack is also designed to be worn across the lumbar region for better weight distribution, instead of the aesthetically questionable tendency of earlier users to wear the pouch as more of a virtual codpiece in the front.
A waist pack can be worn by itself for short outdoor treks, or can be combined with a full-size backpack for an extended hike. Because the waist pack can be comfortably worn on the lower back, it may also be marketed as a lumbar pack in many sporting good catalogs and websites. The term "fanny pack" has become somewhat outmoded in serious sporting goods circles, so shoppers may get better results by asking for either a waist pack or lumbar pack instead.