At some point in my life someone shared a truth with me that I will never forget. "There are two ways to have the tallest building in town...You can work hard and put your heart and soul into building it taller than those that came before, or you can knock down all of the buildings around you."
If by chance you should ever in your life encounter someone who feels the need to whisper and stare, you should take some satisfaction in knowing that is just a pitiful way for them to try in vain to elevate themselves at the expense of others. How sad it must be, to be them.
As far as anyone's weight issues, chances are that with a lot of hard work and effort, they have the potential to lose weight. But those who ridicule, whisper and stare are even more unattractive than any of those they choose to critisize, even though they hide their ugliness on the inside.
Go have fun, enjoy yourself. If anyone dares to look at you in a disparaging manner, then focus all the compassion you can muster and try to feel sorry for them.