Cat broth for overweight cat

My cat wants to eat more than the recommended amount of cat food specified on the bag (Purina Pro Plan Weight Maintenance Formula). Is there a broth or something that I can make to give him (between feedings) that won’t make him fatter. He used to be 17 lbs., but I’ve gotten him down to 15 lbs.

 

Answer from Dr. Gaylord Brown:
Congratulations, losing 2 lbs is hard for people! Imagine losing over 10% of your body weight. Drinking some chicken broth may help, without causing weight gain. It might prove beneficial if you divide the meals into multiple portions during the day.