The aim of this study was to compare gastrointestinal (GI)
hormones and subjective ratings of appetite among
obesity classes, and between classes of
obesity and controls. Ninety-eight adult individuals with
obesity, divided into class I (n = 35), II (n = 44) and III (n = 19), together with 45 controls without
obesity were included in this cross-sectional analysis.
Body weight/composition, and basal and postprandial (after a 600 kcal fixed breakfast) plasma concentrations of acylated
ghrelin, active
glucagon-like peptide 1 (GLP-1), total
peptide YY (PYY),
cholecystokinin (CCK) and
insulin, as well as subjective ratings of hunger, fullness, desire to eat (DTE) and prospective food consumption (PFC) were measured. There were no differences in the plasma concentration of GI
hormones (either basal or postprandial) among
obesity classes, except for
insulin. In general,
obesity was associated with impaired secretion of GI
hormones.
Ghrelin secretion did not decline postprandially in class-III
obesity.
GLP-1 peak for
obesity class I and II was early and lower, while class III showed no postprandial
GLP-1 response. Postprandial PYY response for
obesity class II and III was absent, and class III showed a delayed and shortened postprandial CCK response.
Obesity class II and III had greater basal
insulin concentration compared to controls and postprandial
insulin was greater in
obesity class III versus class II, class I and controls. No differences were found for appetite ratings among
obesity classes. In conclusion,
obesity is characterized by impaired secretion of GI
hormones, with reduced postprandial satiety, particularly in individuals with
obesity class III. This abnormal pattern may lead to
overeating.