How do I respond to people who tell me to "just eat something"?

You can explain to them it's not that simple! I know that "just do this or that" is a very ignorant, frustrating statement, so it's a normal thing to get mad at. But, calmly explaining to them that it's not as easy as just eating something, then maybe they'll understand.

Explain to them that it is the same as telling a cancer patient to 'just get better'. It is far more complex than that, and although you appreciate the sentiment, it is not helping.

I’m sorry but I can’t do that because it hurts me. It makes me feel bad about myself and I’m trying to stay as self-confident and happy as I can but food and gaining weight torment me. I know this may come as a shock to you if you haven’t noticed yet but I’m not happy with the way I look and there’s these voices in my head calling me fat, ugly and telling me I don’t deserve to eat. Even though that ‘something’ could be my favourite food I’ll have to politely decline as I’m not feeling too good, thank you for worrying about me and being concerned but there is no need as I am seeking help for my problems.

Depending on the person and your relationship with them, I would say something along the lines of "I am dealing with a mental illness that is manifested in trouble eating. It hurts me when you say that to me. Would you tell a person with a broken leg to 'walk it off'? I know you care, but when you say that, it hurts."

If you have eaten then politely say no thank you i have eaten and I am full. If you have not eaten tell them that you will eat when you get hungry.

A mental illness is as valid as a physical illness. Just like you wouldn't tell someone who's paralyzed to just walk or to someone who's dead to just hear, someone who has an eating disorder can't just eat. It's a lot more complex than that.

Tel them that it may be easy fo them becasue hey accept the way they look but for you it is a ocnstant struggle and they shouldnt put you on the spot like that

Often this is a complicated question to answer. You don't want to cause a scene, but find it hard to explain without going in too deep. I find that a simple 'it's complicated' usually averts the conversation. If the person is close to you and compassionate, feel free to explain and elaborate further.

I have personally experienced the frusturation of having people who don't understand that eating isn't as easy to some people as it is for them. Only for me if was because I was just never hungry. I'd honestly respond to them "just fly!" And walk away.