The present invention is directed to a golf ball having at least one layer, such as a center, a cover layer, or an intermediate layer, which is formed from a polymer composition comprising at least 25 wt %, based on the total polymeric weight of the polymer composition, of an acid polymer having acid groups, wherein at least 90% of the acid groups are neutralized. The polymer composition also comprises at least 10 wt %, based on the total polymeric weight of the polymer composition, of a non-fatty acid melt flow modifier selected from polyesters, polyacrylates, polyurethanes, polyethers, thermoplastic polyureas, and combinations thereof. The polymer composition is substantially free of fatty acids and their salts and has a melt flow index of from 0.5 g/10 min to 10.0 g/10 min.