The present invention relates to compositions comprising PYY, PYY.sub.3-36, or a PYY agonist, and an anti-obesity agent, useful for the treatment and prevention of obesity and obesity-related disorders. The present invention further relates to methods of treating or preventing obesity and obesity-related disorder in a subject in need thereof by administering a composition of the present invention. The present invention further provides for pharmaceutical compositions, medicaments, and kits useful in carrying out these methods.