that she decided
to go on a DIET...
The Big Bang Theory Season 7, Episode 12
Wrong. She just took a sip
from his Diet Dr. Pepper.
The Big Bang Theory Season 6, Episode 2
"Wil, do you want more Diet Coke?
The Big Bang Theory Season 8, Episode 20
...and their potato-based DIET.
The Big Bang Theory Season 8, Episode 22
It's probably this
stupid DIET I'm on.
The Big Bang Theory Season 7, Episode 2