Proceedings of the nutrition society.

Controversy concerning the relative nutritive merits of protein from plant ‘and animal sources is of long standing. Our conception of the total quantity of protein required has also swung wildly from one extreme to the other. This scientific problem, intrinsically difficult in itself, has been, and still is, emotionally bedevilled by prejudice and sentiment. Recent advances in biochemistry have given us a better appreciation of the ultimate composition of proteins from different sources, and have helped to explain and foretell the ‘biological values’ of different proteins. Nevertheless, we must not forget that we do not eat proteins as such, we eat food containing protein. And evidence is accumulating that the value of the protein may depend to some extent on the vehicle in which it is presented. The time is propitious for stocktaking, for a review of the past, for a forecast of the future. This is the purpose of our conference to-day.