The prefix 'non-' originates from Latin, meaning 'not,' combined with 'diet,' which comes from the Greek word 'diaita,' meaning 'way of life.'

'Non-diet' evolved from the combination of the prefix 'non-' and the word 'diet,' which has been used in English since the 13th century.

Initially, 'diet' referred to a way of life or daily regimen, but in modern usage, it often refers to food intake, especially for weight control. 'Non-diet' specifically negates this modern meaning.