Described herein is a novel, mitochondrial encoded, open reading frame, that leads to the production of a new mitochondrial peptide. Residing within the ND-Two subunit, a specific small nucleotide polymorphism disrupts expression of this mitochondrial peptide, and is correlated with an increase in obesity and diabetes, particularly in certain ethnic populations. In vitro administration of the peptide increases insulin secretion, decreases fat accumulation and improves glucose uptake in muscle cell. Antibodies generated against the peptide can be used for detecting peptide deficiency, in addition to SNP detection, supporting diagnostic approaches. In vivo studies further revealed that administration of the peptide improves glucose tolerance, thereby providing a new therapeutic avenue for a novel diabetes therapy and decreases bodyweight, thus serving as a novel obesity therapy. Generation of synthetic analogs further enhance or abrogated activity relative to the natural peptide.