Carbohydrates are helpful when you are trying to pack on muscle mass. They are required to fuel your intense workouts and keep muscle glycogen levels full.
We suggest you aim to eat around 5-8g per kg bodyweight.
Roughly 50-90 minutes before workout we suggest you consume around 30-50g of protein and 30-50g of carbohydrates. For meal ideas, see here: FoodForFitness Recipes
Your post workout meal is very important, yet many people incorrectly believe that they should eat this meal as soon as possible after training. In reality, the effectiveness of nutrient timing does not require a high degree of precision. Just be sure to eat after training at a convenient time. Aim to eat roughly 0.4g of protein per kg bodyweight and 0.8g of carbohydrates per kg bodyweight at some point after your training. Do not worry so much about the fat content, just be sure to get yourself a large, solid meal to help promote muscle growth.