>>76375431>there might be two types of whole wheat bread and maybe one has way more added sugar than the other, wouldn't you like to know thenThose are actually much more accurately defined in slice serving size rather than in 100 gram servings. Nobody knows how much a piece of bread weighs. Who cares if it's got six grams of added sugar per 100 grams? They want to know how much added sugar is in a slice that they're going to eat. If 100 grams is three slices or something like that, it doesn't matter because you're not, you're only going to eat three slices of bread at once, The serving size is totally amorphous and unuseful. Likewise, if somebody is going to use some amount of ketchup in a dollop that they put on their plate to dip their french fries in, it's much more useful to be able to look at it and say "that looks like about a quarter cup" Even if their estimate is off, because nobody is looking at the little puddle of ketchup and saying, well, that looks like 124 grams., Likewise, people are buying the brand that tastes good, not buying the brand with the lower amount of calories or sugar. In both of your examples, a serving size based on something that people can eyeball, even moderately, inaccurately, is much more effective and useful than a gram serving size.