Brief Answer:
Exercise, Diet and appetite stimulants shall helps

Detailed Answer:
Hi dear.Thanks for your query.

Body mass index is is a measure of body fat based on height and weight that applies to adult men and women.It is an indicator of good health.You have an ideal BMI which is 20(Normal range >18.5-23).An additional BMI (upto 23 for Indians, upto 25 for the rest) can be achieved by increasing your weight.

I would suggest Cyproheptidine Syrup available over the counter at bed time to increase your appetite.

I would like to share a couple of suggestions which might help you gain a healthy weight-

1.Eat 3 meals and 2 snacks in between meals/day.Choose high calorific foods like-
a)Milk shakes, fruits(apple,banana,pineapple,chiku fruit,pear), dry frutis.Add more protein(peanut, soyabean etc).

2.Egg and milk are wholesome food.Take them daily.Especially 100-150ml of warm milk before going to bed brings in a healthy and considerable weight gain.

Start with smaller proportions initially and gradually increase the intake.

3.Plan for fitness regime - Exercise improves your appetite, your physic and removes unwanted fat(bad cholesterol) and toxins from your body.Visit a gym closeby- do weight training exercises.Consult a expert trainer for further advice on a proper mix of aerobic/anaerobic exercise.It is important to strike a balance between exercise and diet for a healthy weight gain.

4.Have plenty of oral fluids.Drink alteast 3-4 liters of water/day.

Scale up gradually by increasing the proportion of food.Increase 250-500kcal/day and monitor if you are improving on your weight every week.

Nutrigain is a good option but it cannot solely achieve the desired weight gain.It is only a supplement but not a substitute for food/diet.

Hope this answers your query.All the best.

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