"I had to lose weight for myself. I was fat and I had to look fit for myself. I didn't lose weight for any film," said the actor.
"Nautanki Saala" director Rohan Sippy didn't ask him to "lose weight".
"I felt, if I would look the same as I looked in 'Delhi Belly', people would typecast me. I had to gain 20 kilos for 'Delhi Belly'. I am happy now and I have a long way to go," he added.
While Kunal's elder brother Siddarth Roy Kapoor is managing director, Studios, Disney UTV, his younger brother Aditya is an actor too.
Thanks to his siblings involvement in the entertainment industry, working "gets easier", he said.
"We discuss a lot about films and other stuff. Things get easy when you have a family from the same field."
In "Nautanki Saala", Kunal has teamed up with Ayushmann Khurrana, Pooja Salvi and Evelyn Sharma. The film is slated for an April 12 release.