All the points everyone has raised are quite interesting.
My point of view is situational.
When a person is depressed then something is done to come out of it and Mahi was eating. So it was quite normal that she was sitting in a room and eating.
Regarding the fat guy she didn't like, I dont think they wanted to show that she disliked the guy because he was fat, but they were raising other issues. Mahi's family thinking that she is fat was ignoring the fact that she has her own ambitions and wishes which because of obesity her mom was ignoring and brining stupid guys for her.
Another interesting point they raised is having a beautiful sibling, her sister. Mahi was always compared with her beauty and proved to be fat and ugly infront of her. Whenever Mahi sees her sister she feels like taking revenge from everyone by getting a handsome guy and marrying him and hence proving everyone wrong. Another comparison they did was with Mahi's brother who was always like a buddy to her with whom she had a normal bro-sis relation. They share joys and sorrows.
A Very interesting point raised in this serial is Why Mahi Wants a Popular Handsome Hunk. She has always looked down because of her obesity. Everyone has made fun of her whether it is office, home or school/college. So she always dreamed for a handsome guy with whom if she walks she feels proud and show the world that they are wrong and someone can love her as well. Someone notices her as well and she means something to someone special.
Regarding Shiv, what she was doing to him was absolutely wrong but it also indirectly shows her desperation. She somehow wants a good-looking guy marrying her and falling for her. But then her friends made her realize that what she was doing was wrong. She is returning same to Shiv what she got from the world. Shiv cares for her and does not deserve that.
Another good point they raised is, why did she fall for any damn handsome guy? A handsome guy if he comes and talks to her, she feels important. She feels happy that a handsome guy noticed her.
What the creatives are trying to show is that external beauty is not related to person's wishes and dreams. An obese person also have dreams and ambitions. World should neither make fun nor pity a person with any kind of defect whether it is obesity or any other disease. Every person has emotions which gets hurt and if a person gets hurt again & again it fills his heart with bitterness and then comes the stage when they want to prove the world wrong.