Needs more weight

Lately I been noticing the one of my chinchillas maybe should be putting on more weight. She is quite skinny, and you can feel her bones. She was always quite skinny when we first got her so maybe she is the way she is. But lately I've been thinking of maybe helping her put more weight on her.



What's a healthy way to put on more weight on a chinchilla?



I've seen things like



Alfalfa rings



http://ift.tt/1rilJz8



Alfalfa cookies



http://ift.tt/1rilHY3



Alfalfa Slims



http://ift.tt/1rilHYh



I'm not sure if they help, but I've seen both before in the store. I've heard the cookies are fatty and shouldn't be giving too often. Anyone have any experience giving these to their chinchillas?



I also heard of Enervite its some kind of supplement for dogs. But giving them a pea sized blob can be given 2-3 times a week or even every day if the chin is very poorly. Not sure if this helps or is good either.



I didn't want to make a chance if this would harm any of them. Thanks again for your time.