What is the best food to eat in case of welling to build muscular body and losing fats after working out in the gym ?

Healthy diet: No magic. Get enough lean protein -- chicken, fish, lowfat dairy, soy, whey protein -- unless you are a strict vegetarian, with perhaps an extra 20 grams after each workout. Avoid greasy and salty foods. As you work out, especially doing cardio, your body will begin to tell you how to eat best. Shun steroids. Creatine & if your doctor is okay an electronic muscle stimulator may be very helpful.

Whole foods: You want to eat a good mix of natural whole foods. Anything that is processed is likely to have artificial or altered ingredients. You should try to get 1/2 to 3/4 a gram of protein for every pound of lean body weight per day. Then get plenty of healthy fats like coconut or olive oil. Lastly keep your total carbohydrate intake under 150 grams per day.