Akira Toriyama hid the biggest secret about Piccolo and his fellow Nameks in Dragon Ball, and that's how they generate energy.

Dragon Ball hosts a plethora of characters, and not all of them are like typical people. While Saiyans are more human in form, they are far from humanity. On the other hand, creatures like Majin Buu are born from evil and destructive tendencies. Similarly, Akira Toriyama has created some fascinating species for the franchise.

An interview between Masayuki Kato, a science teacher and author specializing in biology, and Yudai Okuyama, a researcher specializing in evolutionary biology, led to a fascinating discussion about evolution in Dragon Ball. The focus of discussion for this article would be the Namekians.

Namekians are green-skinned humanoids who also have snail-like features such as antennae. In the Dragon Ball anime and manga, it has been explicitly stated that Namekians do not need food to survive as humans; their only sustenance is water. Namekians' bodies have enzymes that can convert water into nutrients. The digestive system of Namekians can also handle milk, as shown in Dragon Ball Xenoverse 2.