I hate fat people
That's not very kind, especially because in many cases it's a thing that people can't help.
That's completely false, their eating habits are the reason.
Regardless of the reason, it's wrong to judge people based on their physical appearance. It's rude and you're devaluing who they are as a person.
I don't want to be respectful to them. They just don't know how to eat.
How someone else eats isn't a thing that should concern you. How someone looks and what they eat doesn't define who they are as a person and you should be more mindful of how you think about and treat others.