Aspartame is an artificial sweetener sold in the market. It consists of amino acids and provides calories like other amino acids. Yet, it is used as a low-calorie sweetening agent in food items. What is the basis of this use ?

Aspartame is a dipeptide methyl ester composed of two amino acids: aspartic acid and phenylalanine [1]. Like other proteins and amino acids, it provides approximately 4 calories per gram upon metabolism. However, its primary utility as a low-calorie sweetener stems from its intense sweetness potency, which is estimated to be 160 to 200 times greater than that of sucrose (table sugar) [2]. Because it is so much sweeter than sugar, only a minute quantity is required to achieve the desired level of sweetness in food and beverages [1]. Consequently, the total caloric contribution from such small amounts is negligible compared to the calories provided by the much larger quantities of sugar needed for the same effect [1]. Claims regarding resistance to oxidation or non-caloric metabolites are incorrect, as aspartame is rapidly and completely metabolized in the gut into its constituent amino acids and methanol.

Sources

1. [1] https://pmc.ncbi.nlm.nih.gov/articles/PMC3982014/
2. [2] https://pubmed.ncbi.nlm.nih.gov/5452896/