I think the OP is getting some unnecessary flack here.
And I think some posters balance of meat:veg in their meals is way off (with far too much emphasis on meat). Either that or they’re eating far more food than I do (and I’m no slouch!)
I don’t often do roasts (my dc have various different food issues, and balancing food touching on a plate/personal tastes etc gets difficult) so don’t cook a whole chicken often, but some of the amounts being mentioned here are crazy.
I think one poster said they’d cook 1kg chicken breasts for one meal for 5 people. That sounds way over the top to me.
Generally, I use 1 1/2 - 2 chicken breasts (so maybe 350g?) in a meal (depends on size). In a pasta sauce, I’d also add various veg, sauce etc. That pan of food would then feed us (me plus 3 dc - 2 teens who eat a lot and one 9 year old who can be picky) for that meal (obv with pasta as well), and I’d have another meal (ie a portion for each of us) to freeze. Plus 1, sometimes 2 (but not usually) single portion to freeze as dd1 takes hot meals sometimes. So overall, I’d say it makes 7 adult portions plus 2 child portions. And we don’t go hungry, at all.
I think, overall, as a society, we have lost sight of what is a reasonable portion size, and what proportion of meat/veg/carb is supposed to make up our meal. I’m not claiming to be an authority in any way, btw.
Don’t those meal portion plates show that meat is only supposed to make up 20-25% of your meal? Hang on, I’ll try to find an example.