Hi Avoid junk foods,add extra calories to your diet,have Kim Kardashian 4 to 5 meals rather than large 3...add protein rich foods and healthy fats to diet for e.g..egg white...add fibre rich foods like green leafy veggies,carrots,Apple,banana etc....do regular exercise without failure...do bulk up exercises like weight lifting etc....consult dietitian for further details

hi, Body weight is pure mathematics. weight gain = Intake calories - Output calories. To gain weight intake high calorie foods. But if you take more calories with out exercise you will gain unhealthy fat weight. If you increase your activities (exercises) and intake more calories you will gain healthy muscle and bone weight. Carbohydrates is for energy,  protein is for body building and fat is for reserve energy. Though these are interchangeable to some extent and special needs like for hormones etc, you need to balance their ratio. Regards Dr.premkumar