GLOSSARY

High-Quality Protein supplies essential amino acids in suitable proportions and usable forms. This describes nutritional properties rather than a requirement for a particular brand or high price.

Nutritional protein quality concerns essential-amino-acid pattern and usability relative to requirements. It does not rate all food properties such as fibre, fat, salt or price. A tiny amount of a highly scored protein may not meet daily needs, while a lower score does not make a food nutritionally useless.

Adult essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. The body cannot synthesise enough, so the diet must supply them. Essentiality differs from general importance: a nonessential amino acid can still perform vital functions even though direct dietary supply is not always obligatory.

Yoghurt, eggs or a suitable soy product can contribute to a meal. 'High-quality' should not hide portion size: a few spoonfuls of a good source may not meet that meal's intended protein contribution.