Statement 1: Force acting on a body increases its kinetic energy from 200 J to 400 J and this force does a positive work on the body.
Statement 2: A force does a positive work on an object when the displacement is in the direction of force itself.
Both the statements are true and statement 2 is the correct explanation of statement 1.
Any force is said to have done a positive work on an object if that force or any component of it displaces the object in the direction in which it acts. It can be seen that the kinetic energy of the body increases due to the application of force, therefore the velocity of the body increases which implies that the displacement is positive.