Some cats can be more prone to gain weight than others. Even a little extra weight can impact the pet's quality of life and relationship with family because that extra weight can reduce play time, impact mobility and affect the lifelong general health of your cat. Weight problems can be successfully managed through changes in your cat's food. Hills nutritionists & veterinarians developed Prescription Diet® w/d®® clinical nutrition especially formulated to support your cats weight management. In fact, w/d® is clinically tested nutrition for conditions that respond to fiber. * Helps maintain healthy weight * Promotes urinary tract health * Supports a healthy immune system This food requires a veterinary prescription. Hill's is updating their Prescription Diet® packaging and a portion of the name. With Prescription Diet® w/d®, the current descriptor is "Glucose Management-GI"; in 2015 it will be "Digestive/Weight Management". Some pets may need help in switching to an updated pet food. Make the transition easy on your cat's digestive system. To transition, mix your pet's current Prescription Diet® w/d® dry with the new w/d® dry. Over 7-10 days, gradually decrease the amount of the current Prescription Diet® w/d® dry while increasing the amount of new w/d® dry. For some pets, the transition may take slightly longer. Please speak to your vet if you have any questions.