>> reporter: when wheat thins hit the market in 1947, chuck yager was breaking the sound barrier, old blue eyes was singing that "old black magic." fast forward to the '80s, they were still a hit snack but they seemed so very healthy. >> remember sandy duncan. >> reporter: they were wheat and they were thin and that was all before salt became a four-letter word. they decided to embrace the news. in addition to wheat thins, they make just about snack food you love. from teddy grahams to planeters nuts. the usda issued guidelines saying we shouldn't eat more than teaspoon of salt a day. doctors say it contributes to heart attacks and diabetes and risk of stroke. that puts the tasty wheat thin under siege. kraft executives said they're undaunted. >> we're reducing the sodium. we're increasing the whole grain content. going to 100% whole grain. 18% reduction in sodium and still the great taste consumers expect from wheat thins. >> reporter: really? we went to kraft foods campus and asked them to show us how they planned to do that. >> it's a snack. we know that snacks aren't necessarily h