Triiodothyronine, T.S.H., and prolactin in obese women

Basal levels of thyroid-stimulating hormone and prolactin and their response to thyrotrophin-releasing hormone are normal in obese women. Serum thyroxine and triiodothyronine are also normal and do not correlate with body-weight in healthy non-dieting women. After jejunoileal bypass, serum-triio-dothyronine levels fall, and this fall appears to depend more on the reduction in calorie intake after the operation than on the reduction in body-weight per se.