Bollywood superstar Aamir Khan says he was scared of losing out his fan-following when he was offered the role of wrestler Mahavir Singh Phogat in "Dangal" as he had to play an old and fat man.

"I do get scared (of losing stardom). When I heard the story of 'Dangal', I thought I have to do this film. But then I thought that I have just done 'Dhoom 3' and 'PK', and have six-packs and star-image. If I will do this film ('Dangal'), then I will become old and fat. What my fans will think? I hope I don't lose my fan-following," Aamir said here on Wednesday while promoting new film "Secret Superstar".

"Mahavir is a 55-year-old in the film. I am 52. So, there is less difference between us. We are too close. But fans don't know that as they see me as 30-year-old. So, I told the director that I liked the film and I will do it after 10 years when I will be old. They agreed to that too.

"But the story of the film couldn't leave my mind. So, I decided that I should do it and not get afraid of anything," he added.

"Dangal", which released in 2016, went on the break various records at the box office worldwide.

Aamir says being a producer himself, he likes his films to be "economically viable".

"I feel that through the films I am working in the person, who is investing his money, should at least get 10-15 per cent profit. But, I don't look at the box office. If I will take a film thinking how much collections it will make, then I wouldn't have made 'Taare Zameen Par' or 'Secret Superstar'," he said.

Directed by Advait Chandan, "Secret Superstar" is based on the life of a teenage girl named Insia, played by Zaira Wasim, who sets out to follow her dream of being a singing superstar under the confinement of anonymity.

Chandan said that the film is not based on any real life incident.

"All the characters in this film are original and not based on anybody, but they are inspired from people. The people I met during 'Satyamev Jayate' are the ones this film inspired from," he said.

Zaira, whose made her acting debut with "Dangal", considers herself lucky to work with Aamir again.

"I am glad that I got to work with him (Aamir) twice. I never wondered of working with him. I have been very lucky," she said.

"Secret Superstar" is slated for release on October 19.