The physical state of a meal affects hormone release and postprandial thermogenesis

There is evidence that food consistency may influence postprandial physiolo gical responses. Recently we found that homogenization of a vegetable-rich meal significantly delayed the gastric emptying rate and was more satiating than the same meal in solid-liquid form. In this present study we investig ated whether homogenization also influences endocrine and metabolic respons es to the meal. Eight healthy men, aged 21-28 (mean 245) years, were given the meal (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, with water 300 mi; total energy 2.6 MJ) in both solid-liquid (SM) an d homogenized (HM) form, in random order, at 1-week intervals. Variables as sayed were plasma glucose, insulin and glucose-dependent insulinotropic pep tide (GIP) levels for 2 h and diet-induced thermogenesis (DIT) for 5 h. Pla sma glucose pattern was similar after both meals. However, HM induced signi ficantly greater insulin, GLP and DIT responses than SM. Mean integrated ar eas under the curves (AUC) were 1.7 (SEM 0.38) v. 1.2 (SEM 0.33) U/l per 12 0 min (P = 0.005) for insulin, 19.9 (SEM 2.44) v. 16 (SEM 1.92) nmol/l per 120 min (P = 0.042) for GIP, and 237.7 (SEM 16.32) v. 126.4 (SEM 23.48) kJ/ 300 min (P = 0.0029) for DIT respectively. Differences between GIP-AUC afte r HM and SM correlated significantly with differences between insulin-AUC a fter HM and SM (r(2) 0.62, P = 0.021). These findings demonstrate that homo genization of a meal results in a coordinated series of changes of physiolo gical gastroentero-pancreatic functions and confirm that the physical state of the meal plays an important role in modulating endocrine and metabolic responses to food.