'protein-sufficient' is a compound word formed from 'protein' and 'sufficient'. 'Protein' originates from the Greek word 'prōteios', meaning 'primary', and 'sufficient' comes from Latin 'sufficere', meaning 'to provide' or 'to supply'.

'Protein' evolved from the Greek 'prōteios' through French 'protéine', while 'sufficient' evolved from Latin 'sufficere' through Old French 'suffisant'.

Initially, 'protein' referred to a primary substance, and 'sufficient' meant 'adequate'. Together, they now mean having enough protein.