Shortening

Two guys meet every Friday at a certain bar for drinks and just relax. They both have one main thing in common. They are both very short, about 5 ' each. Well one Friday one of them mentions an article in Time magazine, stating if you bath in cooking oil it will make you grow. The other says no way !!! So a week goes by and they meet again and isn't the one guy two inches taller. The other one stills says he doesn't believe it. So another week goes by, and now the one guys is 5' 5". The other stillll doesn't buy it. Well the next week, you guessed it the one guy is 5' 8" and thrilled. Okay okay says the other, it's worth a try. The next week they get together, the first guy is 5' 10" and again thrilled, while the other is 4' 8" now he is Not thrilled. I don't understand it, actually neither of them do. They talk about bathing in the cooking oil. Then one says wait what are you using ??? The second guy say why?? The first guy told him he's using Wesson oil, the second guy say's Crisco. The first guy says NOOOOOOOOOOOOO!!!!! That's SHORTENING....