Obesity is the common nutritional disorder affecting more and more animals every year. Obese individuals have altered metabolism and disorders of many organs. Obesity may develop as a result of specific genetic, metabolic, nervous and environmental factors. Dietary management of obesity requires addressing the underlying metabolism of the animal, normalizing the glucose level and proper treatment of diabetes, which is usually associated with obesity. Novel nutrients like leptin, chromium, carnitine and starch added to the diet as well as new approaches in the obesity therapy are very important in successful weight management and treatment of this common disorder.