I can't comment on the weight gain so far since I've only had for a few days but so far the flavor taste pretty good.. It has a slight aftertaste to it but it's nothing that I can't handle. The other ensure shakes I can't really tolerate that well so I opted for a clear beverage since it's a lot easier to stomach. I wish the calories were a lot higher since I do have acid Reflux and I can have troublesome days eating or just not having an appetite, so drinks like this, really come in handy for meðŸ'ðŸ