how can I help my son, and should I try?

We temporarily living with my younger son, who is 25. I am shocked by the hours he is working, he left the house at 6 this morning, for example, and is still not back at 7.49. For all the two weeks we have been here he's been working 12 hour days.
His position is as an apprentice in an engineering company, and , in my opinion, he has been burdened with a management roll that is too much.
As he's 25, there is nothing we can do. The apprenticeship ends in 5 months. We were intending to go away while we were staying, but I feel the only way we can help is by making sure he has a meal waiting for him, as otherwise he eats rubbish.
So, has/is anyone else been in this position. I'm finding it so difficult seeing him exploited this way.