Mine has been limiting his portion of protein because he thinks it is healthier to eat less of it, fine so I make less, he still eats less no matter how much I make he always leaves almost 2 ounces, about 2 bites really. So not enough to save. then he will go after dinner and eat a huge blob (thinking 4 to 6 T) of PB or cereal out of the box, or another one of the breakfast bars that I make him (which are not as healthy as they could be if I was better at adjusting recipes and could figure out how to replace the sugar). So he is replacing a healthy protein with essentially junk. Not horrible food but not a good replacement. And of course the reason he needs to do that is because he doesn't get enough protein.
Even DD, who is a vegetarian, has told him that she would be thinner if she ate meat because she wouldn't be hungry all the time.