The concepts which have evolved to explain the interactions
between protein and energy metabolism are based primarily on observations made
under conditions of protein and/or energy deprivation. Though they shape much of
our thinking, they are not appropriate to explain the control of amino acid
oxidation when food intake is high. The situation is analogous to the
irrelevance of concepts such as 'biological value' or 'net protein utilization'
for conditions where protein and energy intakes are