Proteins and their constituent amino acids (AA) are key nutrients required for growth, structure, and function of the human body. Nine AA are nutritionally essential because humans do not synthesize them. Therefore, they must be dietarily derived from proteins. Hence, the quality of dietary proteins is predicated on their essential amino acid (EAA) composition and their bioavailability. Animal proteins contain all EAA in correct proportions relative to bodily needs. Plant proteins are limiting in EAA hence are of lower quality. Yet plant proteins are more environmentally friendly and provide important health benefits. Protein intake influences growth, body composition and metabolic health in children. In adults, inadequate or imbalanced protein intake leads to increased body protein breakdown, decreased muscle mass, decreased immunity and increased susceptibility to infections. The superior protein quality of animal proteins and health benefits of plant proteins emphasize the need for balanced intake between plant and animal proteins. Diets that are solely plant-based should consider protein complementation which consists of combining two plant protein sources with complementary AA profile at every meal. For omnivorous diets, an appropriate dietary balance between animal and plant protein should consider both the benefits of plant proteins and the dietary requirement for proteins and EAA at each stage of the life cycle. This presentation will: 1) Discuss current protein recommendations. 2) Present evidence for a higher requirement than current recommendations. 3) Discuss clinical benefits of plant proteins and complementation strategies for combining plant and animal proteins to meet EAA needs.
Glenda Courtney-Martin is a Health Clinician Scientist and Senior Associate Scientist in the Research Institute, Hospital for Sick Children (SickKids), Toronto, and Associate Professor Department of Nutritional Sciences, University of Toronto. Her research is focused on protein and amino acid requirements and metabolism across the lifespan and on protein quality of foods for human nutrition. As a Health Clinician Scientist and clinical dietitian, she provides medial nutrition management for patients with intestinal failure. Her practice-based research is focused on body composition, and metabolic bone disease in children with intestinal failure. She also evaluates contaminants in total parenteral nutrition solutions sold in Canada.