Science Diet Adult Perfect Weight Chicken Recipe Dry Dog Food. Hill's Science Diet Perfect Weight dry dog food provides delicious, breakthrough weight management nutrition with clinically proven technology for: Safe & effective weight loss with visible results within 10 weeks Healthy weight maintenance & long lasting weight support Lean muscle support Recommended for: Adult dogs, including those that are less active, neutered or otherwise prone to weight gain. Available Sizes: 4 lb / 12 lb / 25 lb