s not healthy, but the poster only says they want
to gain weight and not why or how much or whether fat or
muscle and has only 20 days
to do it. So if that's the goal, and I don't know why it is, then eat a lot of simple carbs and cut down on the protein. The same would go for you -- if you eat lots of lean protein, it will in the short term probably result in weight loss, not weight gain, although in the long run it won't last and it might cause health problems down the road.