Hello mate... In my practice, I have found that gaining weight - especially the right kind of weight - lean mass - is the most difficult and slow process. This is particularly true in those who are constitutionally skinny or thin. Losing weight is a piece of cake in comparison. There's a sizeable population - young women - who look to gain weight similarly but despite changing doctors and dietitians, do not get any results. I would reckon - although I dunno very many details about you - you should resistance train and follow a nutrition which prescribes 1. Surplus calorie consumption (in excess of your TDEE - total daily energy expenditure) and - EAT MORE FOOD 2. High-protein, high-carbohydrate diet I've been working on 2 under-19 first-class cricketers with similar goals. In them the problem is even bigger since they expend so many calories on-field. They're coping up well but have to eat tons of food! 😉 Cheers, hope that helps

Gaining weight is not a difficult thing . You need to get few tests done to rule out any cause for you not gaining weight . If everything is right ,I will guide you with detailed protocol. You can review the reports with me