What is the best way to gain mass??

I want to gain more mass not fat. I'm almost 14 and I just weigh 90 something, so I am almost underweight. Don't tell me to excercise and gain muscle, becuase I already have great muscles (abs biceps everything) or don't tell me to eat healthy because I never eat any fastfood or any junkfood. So yeah give me some advice.
Answer:
to gain mass without without fat is not going to happen. you can however minimize the gain in fat by monitoring your portions and your body fat %.you should be getting 1g of protein to 1lb of body weight.you should find out your daily calorie requirement and add 500 to it, while keeping your portions in the ratio of 50% carbs, 30% protein and 20% fats.

---

Try reading "Super Squats" by Randall J Strossen. I don't really like GNC,, Target and Walmart both sell a good whey protein, "Body Fortress" for MUCH cheaper than anything else at GNC.Anything besides that, dpsnutrition.net is almost always cheaper, even after the "super tuesday" discount and what you have to pay in shipping.

---

GNC has plenty of products you can use. They have something I was looking at, thinking about trying called Mass XXX. Kind of expensive though. They got different flavors. Or you can try some kind of whey protein as well.

---

Try eating Low Gylcemic index food.
What is the Glycemic Index?
Not all carbohydrate foods are created equal, in fact they behave quite differently in our bodies. The glycemic index or GI describes this difference by ranking carbohydrates according to their effect on our blood glucose levels. Choosing low GI carbs - the ones that produce only small fluctuations in our blood glucose and insulin levels - is the secret to long-term health reducing your risk of heart disease and diabetes and is the key to sustainable weight loss.
Eating a lot of high GI foods can be detrimental to your health because it pushes your body to extremes. This is especially true if you are overweight and sedentary. Switching to eating mainly low GI carbs that slowly trickle glucose into your blood stream keeps your energy levels balanced and means you will feel fuller for longer between meals.
o Low GI diets help people lose and control weight
o Low GI diets increase the body's sensitivity to insulin
o Low GI carbs improve diabetes control
o Low GI carbs reduce the risk of heart disease
o Low GI carbs reduce blood cholesterol levels
o Low GI carbs can help you manage the symptoms of PCOS
o Low GI carbs reduce hunger and keep you fuller for longer
o Low GI carbs prolong physical endurance
o High GI carbs help re-fuel carbohydrate stores after exercise Check out the following website:
www.marketamerica.com/newme
and look for: Transitions Life Style System
check out the eTools on the site, it has Meal Planner, Exercise Planner, Personal Progress Tracker ...

---