I'm thinking of deliberately not helping fat people at work get more food
What is causing you to want to make that decision?
Fat people need to stop eating. They're already fat. I'm helpping them lose weight.
Its pretty mean to single out fat people in this way. If you want to help them there is probably a much nicer way to go about it aside from making them feel bad about themselves.
You are wrong.
How am I wrong? If people see you are trying to control them they will resent you.