What makes up the one calorie in Pepsi One?
Sucralose contains 391 calories per hundred grams, but it takes only a tiny fraction of a gram to provide the same sweetness as sugar. In the form of Splenda, sucralose has 2 calories per teaspoon, but the FDA allows them to round down to zero. You can round down anything below 5 calories. That’s what the other companies do. Pepsi could do it, too, but clearly they like the marketing angle of “one calorie”. The name “one” suggests “number one”, the best. And perhaps they think that it’ll convey the idea of better taste: “Hey, I can afford one measly calorie, and maybe it’ll taste less like baby aspirin than the zero-calorie sweeteners.