It probably contains 2 servings of tuna, just like a can of soup contains two servings of soup. Most/Many people will use it as a single portion.
Pop, chip, candy makers used to label their products as multiple servings when it was normally used as a single portion and have since been forced to stop.
Exactly the opposite situation to cat food; were I to feed my cat the amouns that producer says I should, i.e. 2 bags a day, instead of half a bag, my cat would probably reach Schwartzfield radius in a month and collapse into a black hole.
> Pop, chip, candy makers used to label their products as multiple servings when it was normally used as a single portion and have since been forced to stop.
Forced to stop? As far as I've ever heard, serving size for all of those things has always been set by law. It's a little weird to say you're "forcing [someone] to stop" doing something you were forcing them to do in the first place.
You can see the Code of Federal Regulations defining the serving size of chips as 30 grams here: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRS... . For "pop" (ok, carbonated beverages), a serving is defined as 8 fluid ounces. Unsurprisingly, a 20-ounce bottle usually contains 2.5 servings of carbonated beverage. How is that the pop, chip, and candy makers' fault?
Pop, chip, candy makers used to label their products as multiple servings when it was normally used as a single portion and have since been forced to stop.