What food should be taken daily to increase the benefits gained from working out at the gym?

A high protein diet is generally recommended for muscle building; though, you should also include magnesium in the diet to ensure your muscles function properly. Protein is especially high in red meats and certain fish, such as tuna. Be warned, though. Red meats tend to be high in cholesterol, and you should be cautious of Mercury overdose if eating large amounts of fish.

Alternatively, you could supplement your protein using protein powder, which can be mixed in to a milkshake or smoothie. This is a common method used by bodybuilders.

I'd also recommend staying hydrated, and keeping your electrolytes up while working out. Water will keep you hydrated, and salty foods should cover electrolytes. Gatorade contains both, which is why it's popular among many sportsmen.