The invention provides methods for promoting weight loss by an animal, promoting weight loss by an animal while preventing or minimizing loss of lean body mass by the animal, preventing a reduction in energy metabolism by an animal, reducing the risk of regaining weight by an animal after weight loss, and ameliorating undesirable animal behaviors associated with reduced caloric intake by intermittently feeding an animal a first diet containing calories that meet the animal's maintenance energy requirements and a second diet containing calories that do not meet the animal's maintenance energy requirements. In preferred embodiments, the described feeding pattern and diets are fed in conjunction with one or more weight loss agents.