A 3-Step Process to Estimate Phenylalanine in Commercial Foods for PKU Management

Phenylalanine (Phe) is a key nutrient in the dietary management of the metabolic disease phenylketonuria (PKU). To give more freedom to PKU patients, we propose a numerical process to estimate the Phe content of a commercial food using the information printed on the label (Nutritional Fact Label and ordered ingredient list). The process is amenable to implementation as a smart phone/Web app and could be integrated into a personalized dietary management software. Our tests show that the results are very accurate (±13 mg per serving) in the vast majority of foods considered. Our approach can be modified to handle any other amino acid for the management of other inborn errors of metabolism. A similar approach can also be used for improving the precision (i.e., increasing the quantization resolution) of the nutrients already listed (e.g., protein).