i've had feeding problems since i was born and it's developed over the years into a mixture of anorexia and bulimia. i've had 4 ED specific admissions into ED units to try and tackle it but it's always been compleatly unsucessfull.
i am about to be diagnosed with SPD by an OT, amazingly despite 6 hospitlisations, numerous diagnosis and having been in the mental health service since i was 15 it's never been picked up until now. what's become clear is that the overeating as a child and the consequential mixed eating disorder is to a large degree if not pretty much exclusively down the SPD and related issues ( i have a number of issues including having had OCD since i was 8). i have had lifelong problems with difficulties with introceptive discrimination especially around whether i was hungry or full. as a child i would eat to the point i was violently sick because hungry feels the same as full to me and i wouldn't know when to stop (or start). as i got older my eating became increasingly odd as i was given more independance. i cannot judge portion size by eye or by feeling. i have to eat in a very infantile way else i run into big trouble. ialso don't really feel any different stomach wise when i am too hungry, i just don't know i'm hungry, i've never been able to. i also don't know when i am thirsty. as a child i would regularly go all day without a drink unless someone prompted me. i've also had life long problems with hypoglycemia, i don't realise my blood sugar is too low until i stop being able to see properly, cold sweat and shake violently.
in ED units they try and tell you you'll get your appetite back eventually and you'll learn to regulate but this has never ever been the case with me before hand or afterwards.
has anyone had experience of similar eating difficulties? does anyone know of any books that i could use to help to plan a meal plan that would be more relevent to SPD diet issues than ED and that would help me learn what is an apropriate amount? because i can't tell i'm too full until it's too late, i am terrified of being sick when i eat so i self induce vomiting so i am empty.

Ah! I just want to let you know that you are not alone!! I've struggled with bulimia since I was 19. My earliest memories are of me hiding and bingeing on masses of sugary foods, not registering that I am full (this has led to a food addiction that I also battle. I'm "average" sized so this is always very surprising to people ha). I can tell when I'm hungry, but only very hungry, and only when I am overfull. I have learned to eat based on calories. This is dangerous for us--but it's the only thing I can do because I cannot determine how much is too much or too little based on size, nor will I be able to feel if it is enough while eating. I stick to a basic meal plan that doesn't change too much (yay for spd and routine!) and I have previously done the calorie math so I can try to not obsess over it throughout the day. Also, it is good for all spd people to eat every 2 hours, so planning small meals and small snacks is helpful. It actually has been helping me to somewhat determine the difference between hunger and other bodily feelings, by knowing whether I have recently eaten or not. I know your post is old, but I couldn't help but respond--even if just knowing you are not alone is all this does for you!

my email is rebekahrosewilson@gmail.com
feel free to email me if you need anything or just want to talk more!!

I'm not helpful for figuring out portions, but one thing that should help is putting food on an alarm. I have issues with remembering to eat partially because I don't feel low levels of hunger, and by the time I feel it hunger and nausea feel the same to me, so having an external method of reminding me "you need to eat", helps a lot.