Brief Answer: Calorie rich as well as nutrient rich foods. Detailed Answer: Hello, I have gone through your query and understand your concern. You have to understand that Little underweight is not at all a problem and in turn studies show it is associated with good health outcomes. But as you are too concerned about this, i have to explain how to gain weight healthily . 1. You should focus on foods that are both calorie rich as well as Nutrient rich foods. 2. Start with nutritious foods and then wherever you can, enrich the foods with additional ingredients like fruit, nuts, and healthy fats. 3. Choose foods that are packed with vitamins, minerals, nutrients, and calories so each bite is loaded with good nutrition. 4. Try to eat six times a day, with each meal (or at least three of them) containing protein, starch, vegetables, and fat. 5. Eat variety of vegetables and fruits. At least have different fruits and vegetables on each days of week. For example adding Pomegranate and beans on Monday, Orange with cauliflower on Tuesday like that. 6. Eat often and choose wisely, and you can expect to gain an average of one to two kilogram per month 7. Have regular physical activity to maintain and gain weight . 8. Taking a little walk before eating will help fire up your appetite. So that you can have good nutrient rich diet. 9. Drink high-calorie juices instead of water whenever you feel thirsty. Try these methods. Really it will be fruitful for you to gain weight. Hope this helps. Please write back for further queries. Wishing you good health.

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