@ TwinsandTrifle you are deluded, and you are clearly being played by your teenager.
No, he is not starving. He has an appetite for yet more food, but starving is the kind of over dramatic language which teenagers use and parents like you latch on to in order to assume that you have to provide a bottomless pit of food, and that if they eat it all then you haven’t provided enough.
This is bullshit. The more you eat, the more your body adjusts, and the more you are able to eat.
Case in point. Years and years ago I went on holiday with my now eXH. We went to Denny’s diner for breakfast, and decided we would have a decent breakfast so we didn’t have to grab lunch in the parks throughout the day. So I had the “grand slam,” which consisted of “2 eggs, 2 bacon, 2 sausages, and 2 pancakes, all for just 2.99” 
I ate it and felt really quite ill afterwards. However, by the end of the week I could eat it quite easily.
One of the reasons why obesity is such a huge problem is because A, we have lost all perspective wrt portion sizes, and B, the fact that we eat more means we adjust to eating more and then want more.
Your son had 4 slices of toast plus eggs for breakfast. He may dramatically say that he is “starving,” but he really isn’t. And tbh all this pandering and crying neglect over children who are clearly fed sufficiently is an insult to families where they really can’t afford to feed their children and where the children actually do go hungry.