he is under nourish only ,he has no other problem.
To gain weight you need to consume more calories every day from healthy foods and choose the right type of exercise.
can occur due to eating disorders, chronic diseases.
Underweight individuals are more prone for heart failures, osteoporosis
problems, and cancers
give him following food item to gain weight
Milk group: Milk, cheese, yoghurt, cottage cheese, ice cream.
Meat group: Meat, fish, poultry, eggs.
Vegetable group: Dried beans, peas, nuts, potatoes.
Fruit group: Fruit juices. Fruits like bananas, mango, chickoo.
Grain group: Cereals, breads, rolls, pasta, pancakes, rice, muffins