When two objects are near each other, increasing one object’s mass would cause the gravitational force of the object to increase.
The formula for gravitational force (F) is

where m and M are the masses of the two objects, d is the distance between their centres, and G is the gravitational constant.
If we hold M and d constant, we can write
, where

Thus, gravitational force is directly proportional to the mass of the object.
If you increase the mass of an object, you increase its gravitational force.