Mix it, Stretch it, Boil it Up! Burn Copper Pot, Burn!

is episode 168 of the original Naruto anime.

Synopsis
Naruto, Chōji, and Sakura volunteer to help Teuchi, whose daughter Ayame was kidnapped by a band of cooking-nin led by Hakkaku. To save her, they must come up with the ultimate ramen recipe. Teuchi tries to teach them how to cook, and the three take advantage of their ninja techniques to make the perfect bowl of ramen. When they rescue Ayame, they became shocked as they noticed she has grown fat due to being unable to resist the cooking-nin's food. To bring her back to her regular self, she eats her father's diet ramen that appears to be designed to make people lose weight from eating it. However in the end, it shows Teuchi had eaten the diet ramen and ended up losing too much weight.