My son six year old, he is very weak and his weight 17 kgs. how can I do for his weight gain

A. Hai good morning !! If kid is active,achieving milestones then nothing to worry about weight. Give 3 meals,2 snacks protein ,calorie rich foods for weight gain. Milk,ghee,cheese,butter,curd,paneer,tofu,nuts (soaked nuts or nuts powder ,dals,dal kichdi,dak makhani,chole,soya,egg,meat in regular meals helps in weight gain.