Protein is used by the body to build, grown, repair and maintain every part of your body.
When we start exercising our body requires extra protein to help repair the muscle damage we cause (this is good damage!) and to grow new muscle. Ladies you need 45-60g protein per day. Blokes, you need more, approximately 65-80g per day.
Muscle is like an engine, it burns through energy (Calories) - so the more muscle we have the more energy we burn. Stock up on high protein meals (15g protein per serve) and snacks (5g protein per serve) after a hard training session.
Protein also helps keep you feeling fuller for longer, so try to include some in every meal.