Use of a peptide having SEQ ID NO: 18 for the treatment of type I diabetes, Type II diabetes, metabolic syndrome, or obesity, or of apetite suppression, or for mitigating insulin resistance, or for reducing an undesirably high fasting serum glucose level, or for reducing an undesirably high peak serum glucose level, or for reducing an undesirably high peak serum insulin level, or for reducing an undesirably large response to a glucose tolerance test.