Talking about the two fields, Diana said: "(They are) very different, extremely different - the nature of the job and what is required from you."
"This (acting) is way more demanding and it has a lot more involvement - physically, emotionally and mentally," the 27-year-old said here Monday while unveiling the cover page of Women's Health magazine, which features her.
Diana started modelling in 2005 for Italian designers Trussadi and Ferre and later for Indian designers like Rina Dhaka, Rohit Bal and Wendell Rodricks.
Diana also shares how her inexperience in Bollywood proved to be a boon while the cast of "Cocktail" was being finalised.
"I was from a completely different world, (with), no film background, I had no acting experience and no training. So I wasn't sure what I was doing there exactly. I just knew I had to meet these people (Imtiaz Ali and Homi Adajania) and I didn't know how I will tell them I am not at all prepared, but I want to meet you anyway," Diana said.
"So all that hesitation and that I was absolutely not confident about myself came through. It so happened that they were looking for somebody like that as the character had all of that in her, and I fit the bill," she added.