First off, at the age of 42 one might feel a little rundown from time to time but it shouldn't be TOO much. At 42 I felt like I could still climb mountains and then someone warned me..."Wait until you hit 45". I said , Naaaw, but then when I hit 45 I felt something that said "slow down a little buddy".
But if he is feeling REALLY rundown then I would have complete bloodwork done, especially pay attention to his iron. You said "We rarely eat meat"...Yes,,,
THAT is a clue.
Meat can build iron faster than ANYTHING you can eat...good red meat. It will build iron faster than any plant or grain foods. Cream of Wheat, however is quite high in iron.
His only problem may be that he needs red meat in his diet. Forget about the cholesterol right now as he needs energy. Then you can always look at the cholesterol, or Statins.
My sister is a doctor, surgeon, and a registered dietician, so I have learned alot on an occassion, about diet