well its halfway done of ramadan so i am sure we all have got used to refraining from food and also we are rewarded for keeping ourself away from food for the sake of Allah. Fasting is completely for Allah and no one else.

From my point of view, NO it is not insulting for me o see anyone eating in front of me. I am sure it depends from people to people.

And best best part is those who do not fast does respect those who fast and it comes automatically to them to refrain from eating and drinking not to make others uncomfortable.