Nutritional assessment with respect to rapid turnover protein (RTP) in the elderly was performed in 22 outpatients (7 males and 15 females, mean age 77 years) who suffered from slight illnesses such as mild hypertension and osteoporosis. Their nutritional parameters were almost within the normal range, judging from body mass index (BMI) and their plasma levels of total protein, albumin, lipids and RTP (transferrin, pre-albumin and retinol-binding protein). Statistically, BMI had a significantly positive correlation with subcutaneous fats and total protein and had a significantly negative correlation with HDL-cholesterol. Retinol-binding protein had a significantly positive correlation with prealbumin, ferritin and vitamin A. Conversely, in 12 bedridden patients the nutritional status was very poor, with their plasma levels of the above markers being significantly lower than those of the controls. We administered an enteral diet (EWH330) to 10 bedridden patients in an effort to restore their nutritional status. As a result, their nutritional parameters, especially RTP showed a significant increase after 4 and 8 weeks of the administration of EWH330. These results suggest that RTP is a very sensitive parameter of nutritional assessment in the elderly.