[sushi_78]

Tofu contains around the same level of protein as egg (12%), but being a very wet food it's fairly filling. If you look at your hamster's diet as a fixed weight of food that they will eat every day (say, 10g), if you feed them 1g tofu every day and they eat 1g less of their dry food, technically the protein level will probably actually be lower if you just look at the percentages. That view sort of looks at a hamster as a machine that can only take a fixed volume of food every day but I doubt things are that simple in reality.

You should be careful with additions to their diet because you wouldn't, for example, want a hamster filling up on cucumber rather than more nutrition foods. In practice this probably wouldn't happen, because most hamsters don't love cucumber enough to prioritise it over seeds and protein-rich foods.

I think that hamsters tend to prioritise more nutritious foods. They tend to go for proteins first, like insects or egg, then the fatty seeds (which are very dense in nutrients), and the grains which are fairly nutrition but not as much as the fatty seeds. Things like hay pellets tend to be left until the very end, if they're eaten at all, which isn't a problem, because they really don't provide a hamster with much nutrition anyway.

I think malnutrition would very rarely be an issue, as long as a hamster is healthy and has a variety of foods to choose from. Obviously, excessive selective feeding is a bad thing, but I think animals probably have some ability to sense what they need, and how to go about obtaining it. For example I have known gerbils to eat sand when they were lacking in minerals, because they know that, in the wild, soil/sand would be a source of minerals.

Dried tofu, having the water removed, is a denser source of protein and other nutrients, so would be a better option if you were looking to maximise your hamster's protein intake.