With any nutrition class,(in college now so this applys even more to HS) it has to be taken with a grain of salt. There is still much to be learned though just a general understanding of Kcal and how they work in our body. Digestive track, slow fast twitch muscle fiber ect...

I am not a true low carber i follow a lower carb regment then that of US guidlines. But carbs are needed when seriously weight lifting.

My point here though is he is probaly intersted in the whole nutriton/food feild and just learn what is feed to him, process it. Then try to challenge it. Instead of giving a speach of a diet that is made up of 55-65% carbs he could give a presentation on a lower carb diet like a 40-40-20 split. And the reasons behind it