It does, but moreso over the long term. Twenty something, athletic types won't notice the impact for a while.
True - it is a time bomb. They won't notice the effect, but it is already there on a small scale.
Pre-game eating habits are important. There are foods that produce lethargy for a few hours after consumption (turkey + mashed potatoes + lots of gravy and stuffing
) and others that produce a little burst of energy.
Beyond that, all it takes is balance. "Balanced diet", including caloric balance. The rest is food fadism. And kale is not food.