I've seen different questions about getting in shape like the importance of age, or how long to workout, or similar questions.
However, my question is about food. I recently started going to gym with a friend of mine, who acts as my trainer too.
He and others keep telling me to use egg, potato, and red meat, and consume protein/bulking powders and have a healthy food/meal plan.
Because of my job, I can't go beyond my routine: ordinary everyday food/meal plan. Eg. eating home-made food one meal a day, eating ready-made food at work, and eating a simple breakfast.
I'm concerned about losing my muscles instead of growing them, or even if not growing, at least keeping them the size they are now, and only form them to get more separate and more rounded.
They talk about catabolism and tell me that your muscles might lack energy after a while and instead of forming or growing, undergo a destructive phase. Thus if you can't change your meal plan, better to not workout.
Please I need your help and scientific explanation for this. Let's forget about me growing muscles. Is it possible to only form my muscles with my everyday meal plan? Without eating more times, or more specific foods. My everyday food contains fast food and healthy food and vegetables and stuff, just like any other guy.