Liquid meal composition, postprandial satiety hormones, and perceived appetite and satiety in obese women during acute caloric restriction

Abstract

Objective: The purpose of this study was to compare postprandial satiety regulating hormone responses (pancreatic polypeptide (PP) and peptide tyrosine tyrosine (PYY)) and visual analog scale- (VAS) assessed perceived appetite and satiety between liquid high-protein (HP) and high-carbohydrate (HC) meals in obese women during acute (24-h) caloric restriction.

Design: Eleven obese premenopausal women completed two conditions in random order in which they consumed 1500 calories as six 250-calorie HP meals or six 250-calorie HC meals over a 12-h period. Blood samples were taken at baseline and every 20 min thereafter and analyzed for PP and PYY concentrations. At these same points, perceived hunger and fullness were assessed with a VAS. The incremental area under the curve (iAUC) was used to compare postprandial responses.

Results: The 12-h PP and PYY iAUC were greater (P≤0.05) during the HP condition (PP: 4727±1306 pg/ml×12 h, PYY: 1373±357 pg/ml×12 h) compared with the HC condition (PP: 2300±528 pg/ml×12 h, PYY: 754±246 pg/ml×12 h). Perceived hunger and fullness were not different between conditions (P>0.05). The greatest changes in PYY and perceived fullness occurred after the morning meals during both conditions.

Conclusions: These data suggest that in obese women during acute caloric restriction before weight loss, i) liquid HP meals, compared with HC meals, result in greater postprandial PP and PYY concentrations, an effect not associated with differential appetite or satiety responses, and ii) meal-induced changes in PYY and satiety are greatest during the morning period, regardless of dietary macronutrient composition.

Figure 1

Pancreatic polypeptide (PP) time course and incremental area under the curve (iAUC). (A) The 4-h PP iAUC for the morning, afternoon, and evening periods. (B) Time course of postprandial PP. (C) The 12-h PP iAUC. Values are represented as means±s.e.m. ↑Meal was eaten. ^aP<0.05 compared with high-protein.

Figure 2

Peptide tyrosine tyrosine (PYY) time course and incremental area under the curve (iAUC). (A) The 4-h PYY iAUC for the morning, afternoon, and evening periods. (B) Time course of postprandial PYY. (C) The 12-h PYY iAUC. Values are represented as means±s.e.m. ↑ Meal was eaten. ^aP<0.05 compared with morning 4-h iAUC within high-protein (HP) condition. ^bP<0.05 compared with morning 4-h iAUC within high-carbohydrate condition. ^cP<0.05 compared with HP condition.

Figure 3

Perceived hunger time course and incremental area under the curve (iAUC). (A) The 4-h hunger iAUC for the morning, afternoon, and evening periods. (B) Time course of postprandial hunger. (C) The 12-h hunger iAUC. Values are represented as means±s.e.m. ↑ Meal was eaten. ^aP<0.05 compared with morning 4-h iAUC within high-protein condition.

Figure 4

Perceived fullness time course and incremental area under the curve (iAUC). (A) The 4-h fullness iAUC for the morning, afternoon, and evening periods. (B) Time course of postprandial fullness. (C) The 12-h fullness iAUC. Values are represented as means±s.e.m. ↑ Meal was eaten. ^aP<0.05 compared with morning 4-h iAUC within high-protein condition. ^bP<0.05 compared with morning 4-h iAUC within high-carbohydrate condition.