As a 19 year old male 135 lbs, how many calories must i eat to gain 1 lb a week?

No need to gain wt: How tall are you? It is not a good idea to add weight. Being skinny is not a disease. As you grow older, you will gain weight and look back fondly at this time when you could eat and not get fat. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk prodFor good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex, if you have sex.