In 2014 Howard Stern interviewed Bryan Cranston and asked how he lost weight so quickly for his role as Walter White on Breaking Bad:
“Stern: When you had chemo and was getting sick playing the part of Walter White, in order to go through rapid weight loss you deliberately didn’t eat for 10 days? True or false?
Stern: How’d you lose all that weight?
Cranston: No carbohydrates. I just took out all the carbohydrates.
Stern: How much weight did you drop?
Cranston: 16 pounds, in ten days.
Cranston: No. The first three days are really hard, ’cause your body’s changing and craving sugar and wants, you know, and then you deprive it of the sugar and it starts burning fat.”
Source: How Walter White lost weight in Breaking Bad, it wasn’t chemo – High Steaks
h/t Tom Naughton