I couldn't find that much but I found the same question as yours and this is another person comment. :3 hopefully that help :D
A diet that can lower your stress looks like something with a lot of fruits and vegis. Making sure you get a least one hour of exercise a day. Plus drinking tons of water and a some juices. Foods I'd consider would be pineapples, strawberries, bananas, cucumbers, carrots, and etc.
Energy homeostasis ..........
The doctor. most likely, is referring to the settling process. In this process, the muscles are still adjusting or on the process of healing so he is experiencing some back pains due to this. Once the muscles are settled in place, he would feel normal again.
A bad attitude or strange behavior different to what they normally display.