Compositions and methods for preventing and treating wasting disorders, such as cachexia and anorexia, are provided. In one aspect, the present invention provides a method for preventing and treating a wasting disorder in a mammal. In one embodiment, the method of the invention comprises administering to such mammal a macrolide and a .beta..sub.2-adrenergic agonist in combination such that the macrolide and said .beta..sub.2-agonist are administered in amounts effective to prevent or at least alleviate said wasting disorder.