Graham, sorry love.
I have had to make this point to my dd, who is over weight. That not everyone who says they eat loads eats the same amount. It look a long time for her to see her very underweight friend who seemed to eat loads was not actually eating very much at all.
So I dd would eat a bowl of cornflakes that would be about three or four of those variety box size one's for breakfast.
Dd would then have sandwiches and fruit for lunch.
At home dd would have another bowl the same size of cornflakes at some point. behind my back
A dinner which was never enough, so she would go back for seconds and finish all of it seconds was behind my back taking the cold rice I had put in the fridge. Say a dinner as an example was boiled rice, green beans and chicken curry.
Now on top of that dd would complain like mad that this other girl ate more than her, and it was so unfair that I didn't let her have chocolate cake and the like.
Well that was through year 7 at school. I explained to dd that everyone's idea of huge amounts of food was not the same, it fell on deaf ears. This girl at school would go on and on and on about all the food she ate telling dd how mean I was not giving dd any chocolate cake etc when dd complained about me, and how her Mum gives her loads of food.
Roll on dd being invited after school to the friends house, friend ate two fork fulls of her dinner, Mum was pushing food on friend all night, friend ate nothing. Friend had a two bread standwich at school, fruit at school and chocolate cake at school and ate it all there.
Another time dd had a sleep over at friends house, friend had no dinner again a couple of nibbles of her dinner, and no snacks in the evening, she left things given to her by her Mum lying around, dd found it shocking friend could leave food lying around, friend ate no breakfast in the morning. So the friend was only eating a lunch each day, and gave off the look to others she was eating loads and had the opinion she was eating loads, when in reality she was undereating and it is my opinion she had an eating disorder.
My dd looked sheepish at me from them on when I pointed out that dd was wrong that I was not mean and that the girl had funny idea's about food, and that dd was eating far too much as she thought that everyone else could eat more than her at school that they were eating loads at home too etc...