You want to stay away from foods or drinks that contain "Sugar" due to the fact that sugar stores fat. Typically, eating sweet sugar foods will make you feel full, thus limiting the amount of good muscle building foods that you will want to eat during the day, like chicken, brown rice, sweet potatoes, red meat, fish, etc.
"Eating sugar is like flipping a switch that tells your body to store fat. And sugar is everywhere—not just in soda, candy, and desserts. It's disguised in refined carbohydrates like bread, rice, and pasta, and even in beer and milk (but rice, pasta and milk can be help build muscle so these foods are often good for muscle growth). However, your body can't tell the difference—it quickly digests and absorbs all these sugars into your bloodstream as glucose.
Here's what happens: Every time you eat sugar, your blood-glucose level rises quickly. In turn, this stimulates the release of insulin, a powerful hormone that signals your body to store fat. There's also a dose response: The more sugar you down at any one time—resulting in a greater rise in blood glucose and, consequently, in insulin—the longer you stay in fat-storage mode."