Let’s have a look at the drastic transformations some actors have gone through:
ARJUN KAPOOR

Many are not aware, but Salman Khan is a big reason behind Arjun Kapoor’s weight transformation. Arjun Kapoor weighed 130kg when he met Salman Khan at the set of his movie, ‘Wanted’. Salman Khan motivated Arjun Kapoor to shed the extra kilos and guided him through process to achieve the figure he had for his Bollywood debut, ‘Ishqzaade'.
“Salman is my elder brother. Once, long back, he had told me that he thought I was cut out for acting, and should try my hand in it. That time, I was obese (140 kg), and couldn’t imagine myself as an actor. Salman literally took me under his wing. I travelled with him for almost two years while he was working on Veer and Wanted, and worked out with him. He believed in me and that’s why I am here today,” Arjun told HT.
SONAKSHI SINHA

Sonakshi weighed 90kgs before entering Bollywood. For her debut film, she shed 30kgs on the recommendation of her co-star Salman bhai!
Sonakshi mentions the following about Salman Khan: “Salman saw potential in me and egged me on to lose weight. I would say his contribution was the highest as I started taking it seriously only after he told me to”.
ALIA BHATT

Alia Bhatt wasn't always so toned and slim before her debut. A video clip of her audition where she was seen in her chubby avatar went viral a couple of years back and fans were shocked to see her like that.
In fact, it was a push from her Student of the Year director Karan Johar which made it happen. Karan Johar wanted her SOTY character, Shanaya to be 'young, hot, slim and perfect' and with that cue, Alia trained hard and lost 16 kilos.
R. MADHAVAN
R Madhavan has disappeared from the B-Town scene after Tanu Weds Manu Returns (2015) and Saala Khadoos (2016). Initially, he didn’t seem to have an issue being overweight, as proven by this comment:
"From Salman (Khan) to Bipasha to my wife, everybody wants me to get some seven-pack or eight-pack abs, but I am just happy with my family pack."
But it seems like Maddy finally gave in to all the pressure -- his new lean, dashing look is the proof!
SONAM

Sonam weighed 86 kilos before she signed her first film, Saawariya. She dropped 30 kilos to get the look in her film. In an interview, she credited her mother for her weight loss journey.
“In all fairness, it was my mother who helped me get rid of my excess weight. The first thing she did was to keep me off the stuff I was so fond of as a teenager- chocolates, ice creams, fried foods and sweets.”
ImageSource: Pinterest, Fabbon, Times of India, Bollywood shaadis