The term well-being appears in both the final UN Charter and in early drafts from July1943 (Notter, 1949: 479), but unrelated to health. A letter from Gautier to Biraud revealsthat the term was added in response to the International Labour Office (ILO)’s ‘Phila-delphia Declaration’, which spoke about ‘the promotion of . . . health, education andwell-being’ (International Labour Organization, 1944). Gautier argued that the WHOshould ‘defend the ground’ against the intrusion of ILO, which happened at a time whenhe was trying to expand the WHO’s domain to include social security, housing, andnutrition.
Adding "social well-being" to the definition sounds like a broad, humanistic goal, but it actually started as bureaucratic turf-war posturing against the ILO. The term is so vague that it's nearly impossible to measure clinically, showing how political posturing over organizational scope shaped the language we still use today.