Protein?

You could supplement w/protein shakes or fortified bars. If I'm really struggling to protein, I'll grab a Pure Protein or Quest bar. But I like the Quaker and Nature Valley bars with added protein. Fish, cottage cheese, greek yogurt, and nuts are also high in protein. I make our own beans by the crockpot full and lentils on the stove top so we always have them in the house and I can control the sodium.

Yoghurt. Fruit. Nuts. Meat. Eggs. Shakes wont make the difference

You're going to find the most protein in meat, poultry, and fish. Other good sources are Greek Yogurt and eggs. When you start talking about dairy and nuts, yes...these things do contain protein, but are more considered good sources of dietary fat.

You could also supplement with whey if you need to...but if your protein goals are "normal" you can probably get all you need with food.