you can take all my fat.. i am more than happy to donate to you :))

jokes apart..if you want to put on fat then put on muscles and not just fat. each regular diet with supplement of carbohydrate and exercise. it will build your muscles and muscles weights more than just fat and healthy too.

otherwise you can just dig into chocolates, sweets, ice cream, cheese and in 3 months you will reach your 5-6 kg.