In order to increase weight pl. Look at following points: 1. Rule out any digestion issues such as frequent stools, sticky or smelly stools, frequent stomach upsets, headaches or acidity, worm infestation etc consult a doctor. 2. Eat a 4 main meals n 2 to 3 small snacks. 3. Instead of focusing on just calories n fats , include nutrient dense foods such as sprouts, milk, curd, nuts, figs, soy milk, fruits, leafy vegetables, colored veggies. 4. Eat small portions but it should be calorie n nutrient dense such as dal paratha, sprouts with muesli, til / gnut ladoo, fruit n veggie smoothies, hung curd with dry fruits etc. 5. Regular exercise 6. Chew food properly n concentrate while eating 6. You can take multivitamins and calcium supplement to supplement your diet.