Soft drink companies are resisting FDA plans to put the percentage of the recommended daily amount of sugar on products, as opposed to grams per serving (the gram being a unit Joe Average USA has no clue about). For the sake of reference, one can of Coca Cola contains 130% of that amount, I believe.
But I think there's an easier way to determine this amount. It's simple. The recommended daily amount should be:
That amount which, on live TV, the CEO of the soft drink (or other) company is prepared to consume in a single sitting.
“Coca Cola can be part of a balanced daily diet.” [actual quotation by actual big person during London Olympics, sponsored by Coca Cola]
“Fantastic. Okay. Here are eight cans of cola. Drink them.”
“Well...perhaps we shouldn't get carried away here.”
“Oh, okay. Seven. Drink seven.”
“Fair enough. Six. Go on. Drink.”