Thin privilege is not being denied a necessary medical procedure until your life is actually in danger.

My father’s girlfriend lived with a hernia for several years because doctors wouldn’t perform surgery until she lost weight, citing her size as a risk which outweighed the benefits of the operation. To cut a long story short, after seven years living with the hernia, it became strangulated, and the resulting ischemia led to necrosis and sepsis that could easily have killed her. Miraculously, the much more complicated medical procedure to deal with this was performed without any concern being expressed over her weight at all… despite the fact that, y'know, it could all have been avoided if they’d treated her like a person and not a BMI in the first place.

Putting this into context, she’s around 280lb at 5'4", she’s in her late 50s, and has been at or around this weight since her late teens. Much to her amusement (and the consternation of a string of fatphobic GPs and practice nurses) she has none of the health problems that she’s been warned are supposedly inevitable for a person of her size - her cholesterol is low, her blood pressure is ideal, her blood sugar is ideal, she works in a physically active job that entails spending most of the day on her feet, she’s a keen cyclist, and up until a couple of years ago was still running 5k and 10k races every few months for charity. But context is irrelevant. No one should be denied access to necessary surgery, because regardless of size, health or lifestyle, we all deserve to be treated like human beings. Except, according to the NHS, if you’re fat.