Hi Welcome to HealthcareMagic According to your height and weight, your Body Mass Index (BMI) is 17.3 which is considered as underweight.Ideal body weight for your height should be between 80kg-85kg. In order to increase your weight your diet should be high in protein which helps to increase the muscle mass and stamina in the body.Eating foods rich in protein includes whole pulses, legumes, milk products, soya products, peanut butter, nuts and dry fruits.Take foods like fruit milkshakes,dry fruit milkshakes, lassi, buttermilk, whole milk,Flavoured soy milk,tofu(soy paneer),groundnut chikki/ burfi, green banana and you can try using protein supplements like ENSURE or RESOURCE HIGH PROTEIN which can be taken along with milk twice a day.Try aviod taking junk foods like oily fried foods,highly saturated sweets, carbonated drinks and alcohol which will eventually suppress your hunger.Along with dietary modifications exercise is also a factor which has to be taken care and stay hydrated.Weight gain is a slow process and it needs patience in going forward with the diet.