Herbal remedies for underweight

I always lose weight, I want to regain weight. What will I do to this?
WHEN one loses weight for no apparent reasons, a complete medical review is necessary to determine the cause and eliminate any malignant process.
The common causes of weight loss are: digestive disorders, febrile disease, intestinal parasites, excess physical activity or out of proportion to the amount of food taken in and hormonal disorders such as hyperthyroidism.
To gain weight, the diet must meet three requisites:

1. It must provide sufficient calories in the form of carbohydrates. This way the body can utilise dietary proteins to synthesize new proteins. If there are not enough calories in the diet, the body uses proteins for energy and not for body tissue.
2. It must provide an adequate supply of B group vitamins, which are essential to the metabolism of carbohydrates, converting them to energy.
3. It must maintain the correct proportion of calories from the three energy nutrients: carbohydrates (60%), fats (30%) and protein (10%).

With the goal of taking in as many calories as possible, concentrated foods that are also rich in B vitamins are recommended.
Food for weight 
Wheat: Wheat is great source of energy, starch, proteins and B group vitamins. Whole-wheat flour and cereal should be basic elements in any weight-gain diet.
Legumes: Legumes are excellent sources of proteins, carbohydrates and minerals. They are concentrated foods whose abundant use contributes to nitrogen retention, which helps synthesize new proteins, adding to body mass.
Potato: Potatoes supply high quality proteins as well as easily digested carbohydrates, vitamins and minerals, all of which contribute to tissue formation and weight gain.
Breadfruit: This tropical fruit is rich in starch, nutrients and a good source of energy. Eaten liberally with beans or vegetables, it promotes weight.