"The nutrition is bad."
Translation:Die Ernährung ist schlecht.
"Ernährung" comes from the verb "ernähren" which means to feed. "Ernährung" would be the concept of feeding on, but it usually refers to a long-term proccess: "nutrition", which basically is a word which refers to all your feeding habits.
"Nahrung" ist basically any piece of food. It is a synnonym of "Essen".
I'm sorry this sentence makes no logical sense. Nutrition cannot be bad or good. Nutrition is a noun refering to a sum of macro and micronutrients. Failure to assimilate a number of important nutrient would be call poor nutrition. I'm not sure you can call anything good nutrition. Arghh, this makes me so mad