I nearly skinny 20 yr. I tried sooo much to gain weight , but it doesn't help full. My meal quantity is normal , means i eat food as a healthy person eat. Me and my brother eat same food and in equal quantity but he is healthy and mascular but not i . My digestion power is fast , it take few hour to digest but the nutrition/nutrients Doesn't absorb properly . I exercise daily but no any good response . Sooo please help me to gain weight as well as muscles.