dont eat alot before a work out, liquids will probally make it hard. If your overweight, and eat alot before a work out, it might be hard. working out doesnt turn calories into muscle, so eating afterwords wouldnt effect anything unless your trying to lose weight, but you still need 2,500 calories if your going to buildmuscle, or youll probally just get thin. this isny my area of expertise.
Work out first. Doing so quickly boosts your metabolism levels so the food you eat afterward burns efficiently & thoroughly the rest of the day/night. (But do drink some water beforehand, so you don't become dehydrated while exercising.)