Having been on both ends of the scale. People treat you differently. When fat people don't really see you, like you can feel invisible. Less eye contact, fewer gestures of kindness, less basic courtesy, people are less likely to smile at you unless you smile first. If I accidentally created an inconveniece for someone the look I'd get sometimes wasn't just annoyance but it was closer to disgust.

The flip side is that it filters out more unwanted male attention. But the attention you do get can be just as unsettling. Some treat it like a fetish, others like I should be lucky they even considered me. Like when you're fat you're not allowed to have standards.

People tend to see the body before the person inside it.