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/m(2)) 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.