Glucagon-like peptide-1 release and satiety after a nutrient challenge in normal-weight and obese subjects

Abstract

The present study was conducted to assess whether glucagon-like peptide-1 (GLP-1) release and appetite after a breakfast with or without an additional galactose/guar gum stimulation is different in normal-weight compared with overweight/obese subjects. Twenty-eight overweight/obese (BMI 30·3 (sd 2·7) kg/m2; age 44·3 (sd 9·7) years) and thirty normal-weight subjects (BMI 22·8 (sd 1·4), age 31·5 (sd12·8) years) participated in a crossover study. Fasting and postprandial plasma GLP-1, insulin, glucose and free fatty acid concentrations were measured in response to either a galactose (50 g)/guar gum (2·5 g) load (836 kJ) and a standard breakfast (1·9 MJ; GG), or water (250 ml) and the standard breakfast (W) every 30 min relative to the ingestion for 120 min. Appetite was assessed using 100 mm visual analogue scales. GLP-1 concentrations were significantly increased after GG at 30 and 60 min compared with W in both groups. Plasma GLP-1 concentrations in the W condition were higher in normal-weight than overweight/obese subjects (P=0·03). No difference was observed in the GG condition between groups. Satiety was increased in normal-weight compared with overweight/obese subjects in the GG condition at 30 (P=0·02) and 60 (P=0·04) min. We conclude that after a standard breakfast with water, GLP-1 release was lower in the overweight/obese than the normal-weight subjects. However, postprandial GLP-1 release in overweight/obese subjects was no different from that of normal-weight subjects when galactose/guar gum was added to the breakfast. The latter was not mirrored by subjective feelings of satiety. Disturbed perception of the physiological feedback of a satiety hormone rather than disturbed feedback itself might contribute to obesity.