Amino acid variability, tradeoffs and optimality in human diet

Abstract

While the quality of fat (e.g. saturated/unsaturated) and carbohydrate (e.g. whole grain/simple sugars) intake has been of great interest, less attention has been made to the type of protein and resulting amino acid intake profiles in human diets. Studies at the molecular level however demonstrate that dietary amino acid intake produces substantial effects on health and disease such as cancer by modulating metabolism. How these effects may manifest in human food consumption and dietary patterns is unknown. We developed a series of algorithms to map, characterize and model the landscape of amino acid content in human food, dietary patterns, and individual consumption including relations to health status, covering over 2,000 foods, ten dietary patterns, and over 30,000 dietary records. We found that the type of amino acids contained in foods and human consumption is highly dynamic with variability far exceeding that of fat and carbohydrate. Some amino acids positively associate with diseases such as obesity while others contained in the same food negatively link to disease. Using linear programming and machine learning, we show that these health trade-offs among can be accounted to satisfy biochemical constraints in food and human eating patterns to construct a Pareto front in dietary practice, a means of achieving optimality in the face of tradeoffs that are commonly considered in economic and evolutionary theories. Thus this study may enable the design of human protein quality intake guidelines based on a quantitative framework.