I've seen one too many concerned users of the V4 Tamagotchi Connection about their Ichigotchi being underweight, going as low as 0lbs.  Most of them are even panicking, thinking that their beloved pet will die because of this, or a major tamagotchi glitch has come upon their electronic gadget.

Don't fret Tama caretakers.  It's not a bug or even a virus!  Apparently, Bandai has placed zero as the Ichigotchi's base weight. 

I have photos of my Ichigotchi as well to prove this fact.

Maybe strawberry-like Tamagotchis really are light. :)