Q: What type of “people food” can my ferret eat to up his weight?
A: I recommend no people food for ferrets. Normal, healthy ferrets should be fed a premium diet specifically formulated for ferrets. There are a number of excellent choices available in most countries where ferrets are pets.
When a ferret is sick, a number of products are available to help the ferret make it through its illness.
For both the healthy ferret diet and the diet for ill ferrets, extensive research has gone into the development of the products, and I cannot imagine feeding people food in place of these well-studied diets.
In some cases, when a ferret is very sick and has turned its nose up at different foods, a mixture that includes baby food (without sugar) in a concoction meant to get the ferret eating again might be suggested. In general, there is no people food I would recommend for ferrets.