Im a 20years old teenager and i want to gain weight. what can i do to increase my weight?

Weight gain is easy!: Weight gain is easy, but a healthy & meaningful gain in lean body mass should be your goal. Don't take Anabolic steroids for quick results that will sacrifice your future quality of life! exercise vigorously, eat balanced meals, stay hydrated. Explore medical reasons why you have difficulty gaining--thyroid/ adrenal problems, diabetes, malabsorption, pancreas insufficiency, crohn's, infection...

Eat healthy foods: that are high in calories. Eat 6 meals /day. Work on strength training to build large muscle groups. Work out w heavier weights w fewer repetitions. Sleep at least 8 to 9 hrs/night. Hydrate well w water. Foods to help w healthy weight gain: almonds, cashews, pecans, sunflower seeds, flax seeds, walnuts, hummus, avocados, granola, trail mix, dried fruits, protein shakes, protein bars, lean meats