Enhanced thermic effect of food, postprandial NEFA suppression and raised adiponectin in obese women who eat slowly.

OBJECTIVE: Meal duration may influence cardiometabolic health. The aim of this study was to explore postprandial effects of meal duration on human metabolism and appetite. DESIGN: Postprandial comparisons following a standard meal eaten slowly over 40 min ('D40') and the same meal eaten quickly over 10 min ('D10') on a different day. Each participant therefore acted as their own control, thereby limiting confounding factors. PATIENTS: Obese premenopausal Caucasian women (n = 10) with confirmed normoglycaemia were recruited from an obesity clinic at UHCW, Coventry UK. Subjects underwent whole-body calorimetry (8-h) on two separate days. MEASUREMENTS: Following standard lunch (D40 vs D10), 4-h postprandial analysis included thermic effect of food (TEF) and bloods taken at predefined times (including baseline fasting). Analytes included lipid profile, adiponectin, insulin, glucose, ghrelin, leptin, endotoxin, gut and pancreatic hormones. Appetite was measured using visual-analogue scales and ad libitum food intake at subsequent meal. Paired sample t-tests [including area under the curve (AUC)] were used to compare D40 and D10 trials. RESULTS: Postprandial TEF (over 240-min) was significantly greater for D40 than D10 [mean (SEM): 80·9 kcal (3·8) vs 29·9 kcal (3·4); 10·6% vs 3·9%, respectively, P = 0·006; AUC 71·7 kcal.h vs 22·4 kcal.h, respectively, P = 0·02]. Postprandial plasma NEFA was significantly lower, and adiponectin levels were significantly higher for D40 than D10 [AUC (SEM): NEFA 627 µmol.h/l (56) vs 769 µmol.h/l (60), respectively, P = 0·02; adiponectin 33·4 µg.h/ml (3·9) vs 27·3 µg.h/ml (3·8), respectively, P = 0·04]. Other postprandial analytes and appetite measures were equivalent. CONCLUSIONS: In obese women, eating slowly associates with enhanced TEF, elevated serum adiponectin and suppressed NEFA.