The present study was carried out to see if either the volume of water or the duration of ingestion time influence the postprandial blood glucose and insulin responses in non-insulin-dependent diabetic (NIDDM) subjects. Small test meals containing 40 g carbohydrate as rye bread (100 g) with butter (10 g) and tomatoes (75 g) were given to 10 NIDDM subjects. The meals were taken in random order with either 90 or 600 mL tap water. The meal with 90 mL tap water was ingested over 10 and 30 min. The glycemic responses to isocaloric meals of large and small volumes were similar (338 +/- 56 vs 384 +/- 67 mmol/L.240 min) as were the insulinemic responses (29,424 +/- 6512 min vs 27,140 +/- 6548 mumol/L.240 min). An extension of eating time from 10 to 30 min did not alter the glycemic (384 +/- 67 vs 370 +/- 54 mmol/L.240 min) or the insulinemic response (27,140 +/- 6548 vs 35,670 +/- 10,245 mumol/L.240 min) in the NIDDM patients.