I don't pretend to know more than CS or Tweakle but I really don't think there's a problem. Let's look at it:
He's 17 years old. 6' tall. 155 pounds. And "ripped" according to his own words. And that's while eating:
Breakfast- eggs, sausage, milk , pop tart
Next - i'll bring a turkey sandwich to school to eat before lunch
Lunch- School lunch varies
Afternoon - 2 yogurts, ramen noodles, milk
Dinner - Fried chicken, salad, milk, cookies
Late night- ramen noodles again, frozen pizza
Now, one by one . . .
Breakfast: who can complain about eggs, milk, & sausage? Some fat and probably not the most "heart healthy" but again, he's 17. He won't drop dead. Pop-tarts . . . sugar. So what? It's not that bad. And he's got some carbs and probably feels pretty full after this meal. If they all were like this, he wouldn't be 155 anymore.
Next: turkey sandwich. Good. Probably need to eat 2 of them and really pile on teh turkey. Add a lot of mayo to get some more cals. What's the problem? It probably should be on whole wheat bread or something. And rather than mayo, he should probably eat a bagfull of almonds or something (I'm being serious, not snarky).
Lunch: school lunch. OK. This sucks. LoL Eat at least TWO and a half-gallon of milk thta you bring from home.
Afternoon: milk, raman, 2 yogurts . . . starchy carbs . . . again, so what? He could eat a "whole grain" carb instead or something but this won't hurt him. Yogurts have sugar, which should probably be minimized but 2 measly yogurts won't hurt a 17 y.o. Milk. MMmmm. . . good. Drink more. He doesn't have enough protein here. That's a problem.
Dinner: fried chicken, milk, cookies, salad . . .a few cookies won't hurt anyone AND THIS GUY IS 155 FREAKING POUNDS! He's clearly not bingeing and getting fat on cookies. OK, here's a simple fix: no more than 2 cookies for dessert. Fried chicken? Tastes good. Probably eats a lot and gets a lot of protein. And he's still 'ripped' so what's the problem? Milk. Good. Drink more. Salad. Good.
Late night: more raman & pizza. LoL Not so good. WHERE'S THE PROTEIN? I was gonna' say drop some of these carbs but what's the point? HE'S NOT GAINING WEIGHT. The carbs probably help fuel good workouts the next day. My only beef here is he's not getting enough BEEF! Eat your raman and pizza. Wash it down w/ a half gallon of milk. But before touching those carbs, WOLF DOWN A STEAK OR A DOZEN EGG WHITES OR A CARTON OF COTTAGE CHEESE. Protein first. Then whatever you want. This ensures he gets enough protein.
I just don't see it as a major problem for a young guy having trouble gaining weight. Some sugar and starchy carbs won't matter much. I will say that he DOES need more protein. Otherwise, not healthy or great, but not that bad. He'll survive. Just needs MORE FOOD.