Not sayin' U.S. food labeling laws are a little wonky, but a 2.8-ounce packet of tuna fish and a 5-ounce packet of same both claim to contain a single serving. One of them is a damn liar... and possibly both, since neither is really the right amount for a single sandwich. 
@xinjinmeng Really? I think of myself as a small sandwich eater. Then again, that's measured against the positively brobdingnagian sandwiches I usually get from sandwich places. You know the ones – if it's not a softball-sized knot of pastrami in the middle, it's way too much bread. By comparison, four ounces of tuna fish on generic pre-sliced bread seems kinda tame.
Keet … likes … softball-sized … knot. Also noted. 💙
@xinjinmeng Oh, I see what you're playing at. *grin*
@ElectricKeet
Keet … eats … big …sandwiches. Noted.