Aspartame, the common artificial sweetener used in diet sodas and 'Equal,' was discovered by accident. Chemist James M. Schlatter was working on an anti-ulcer drug and happened to lick his finger to pick up a piece of paper. He noticed an incredibly sweet taste. Aspartame is a dipeptide made of two amino acids: aspartic acid and phenylalanine. It is approximately 200 times sweeter than sucrose (table sugar). Because it is so sweet, only a tiny amount is needed to provide the same sweetness as sugar, making the caloric contribution negligible. However, aspartame is not heat-stable and breaks down at high temperatures, which is why it is rarely used in baked goods. It remains one of the most thoroughly tested food additives in the world.