What a lot of people don't understand is that when your training and exercising the most important part of it all is your personal nutrition (what your putting in your body). Because if you don't put the correct things into your body you wont get what you want out of it.
So for example, if your training for 1 hour a day using weights but after you've had a workout your not putting any protein foods into your system such as; meats, eggs, protein supplements. Your muscles wont have anything to take in then they wont repair therefore wont grow!But also if your not eating enough Carbohydrates you wont have enough energy to train.
But its not just the energy, you'd slowly start to feel weak, constantly tiered, then your immune system will slowly start to slow down and then you'd be frequently ill.So to achieve the body you desire or to become the fitness level you dream of you will always need a balanced diet. Fats, Crabs and Proteins are the key to being healthy and keeping fit.