The purpose of this investigation was to learn whether the thermogenic effect in man of sucrose and glucose was similar and whether normal weight and overweight subjects responded in a similar manner. Dietary-induced thermogenesis was calculated for the period 15 to 180 min after ingestion of sucrose or glucose in six normal weight and five obese subjects. The metabolic rate was calculated from the oxygen consumption and carbon dioxide output utilizing the ventilated hood technique. In normal weight subjects, the total dietary-induced thermogenesis was significantly greater after sucrose than after glucose (p less than 0.005) but the difference was much less marked in the obese subjects.

Background: Glucagon-like peptide 1 (GLP-1) is an incretin hormone that stimulates glucose-induced insulin secretion, increases b-cell proliferation, neogenesis and b-cell mass. In adults, plasma concentrations of amidated GLP-1 are typically within the 5-10 pmol/l range in the fasting state and increases to w50 pmol/l after ingestion of a mixed meal. Research design and methods: We measured plasma glucose, insulin and amidated forms of GLP-1 prefeed and then at 20 and 60 min post-feed following ingestion of a 60-70 ml of standard milk feed in preterm (nZ10, 34-37 weeks) and term newborn infants (nZ12, 37-42 weeks). Reverse-phase fast protein liquid chromatography was used to characterise the molecular nature of the circulating GLP-1. Results: Mean birth weight was 3.18 kg and mean age at sampling for GLP-1 was 7.7 days. The mean basal GLP-1 concentration was 79.1 pmol/l, which increased to 156.6 pmol/l (G70.9, P!0.001) and 121.5 pmol/l (G59.2) at 20 and 60 min respectively. Reverse-phase chromatography analysis suggested that the majority of GLP-1 immunoreactivity (O75%) represented GLP-1 (7-36) amide and (9-36) amide. Conclusions: Basal and post-feed amidated GLP-1 concentrations in neonates are grossly raised with the major fractions of circulating GLP-1 being (7-36) amide and (9-36) amide. Elevated GLP-1 concentrations in the newborn period may have a role in regulating maturation of enteroendocrine system and also of increasing pancreatic b-cell mass and regeneration. The high levels of GLP-1 may be due to immaturity of the dipeptidyl peptidase IV and or lower glomerular filtration rate in the neonatal period. Further studies are required to understand the role of GLP-1 in the neonatal period.

Fasting adult male rats were given, by orogastric tube, sucrose, glucose, glucose with fructose and water, and the metabolic rate for the ensuing 150–180 min was measured. It was found that there was an increase in metabolic rate after all sugars, greatest after sucrose and least with glucose and with fructose. With the glucose:fructose mixture the metabolic rate was greater than glucose and less than an equimolar load of sucrose. The respiratory quotient after glucose was less than that after fructose, whereas with sucrose it was greater than an equimolar mixture of glucose and fructose.