Hi! I am not Cathe, but I do have a certification in nutrition. Yes, performance is always better if you have better eating. Your body is like a car and needs proper nutrition to run effectively. You should supply your "engine" with enough fuel (calories) coming from wholesome foods like compex carbohydrates, fruit, vegetables, lean proteins, and healthy fats. Eating unhealthy junk does nothing for your engine, except give you a spare tire!!
Hope this helps,
Kristen