'protein-focused' is a modern compound formed from 'protein' + 'focused'. 'protein' originates from Greek, specifically the word 'proteios', where 'proteios' meant 'primary'. 'focused' originates from Latin, specifically the word 'focus', where 'focus' meant 'hearth' and later 'center'.

'proteios' (Greek) was adapted in the 19th century into the scientific term 'protein' (coined in the 1830s to name primary biological molecules). 'focus' came from Latin 'focus' into Late Latin/Medieval Latin and then Middle English as 'focus'; the verb 'to focus' (to concentrate attention) developed later, producing the adjective 'focused'. The compound 'protein-focused' arose in modern English usage (20th–21st century) in nutrition and health contexts.

Initially 'proteios' meant 'primary', and the scientific term 'protein' came to mean the primary class of biological macromolecules; 'focus' originally referred to a 'hearth' and then a 'center', later developing the sense 'to concentrate attention.' Together, the compound now means 'placing emphasis on protein'.