Consequences on islet and incretin hormone responses to dinner by omission of lunch in healthy men

Background: Omission of breakfast results in higher glucose and lower insulin and incretin hormone levels after both lunch and dinner. Whether omission of lunch has a similar impact on the following meal is not known. Aim: This study therefore explored whether omission of lunch ingestion affects glucose, islet and incretin hormones after dinner ingestion in healthy subjects. Materials & Methods: Twelve male volunteers (mean age 22 years, BMI 22.5 kg/m2) underwent two test days in random order with standard breakfast and dinner on both days with provision or omission of standard lunch in between. Results: The results showed that throughout the 300 minutes study period, glucose, insulin, glucagon and GIP levels after dinner ingestion did not differ between the two tests. In contrast, C-peptide, and GLP-1 levels were 26%-35% higher at later time points after dinner ingestion when lunch had been omitted (P <.05). Conclusion: We conclude that omission of lunch increases GLP-1 and insulin secretion and possibly also insulin clearance resulting in unchanged glucose and insulin levels after dinner ingestion