Protein powders

It's just protein, can't see why not... unless dairy is on your no go list. Or there are things in whey protein that are on your no go list also. Some powders have all sorts of junk added.

A whey protein isolate has lactose sugars removed, so that would be your lowest carb option. If that's not a concern then probably consult google for your best lowest carb options. Watch out for artificial and sweetened additives. Cold pressed it also what you want.

I'd recommend the one I use as it is low carb, 0.25 of a gram per serve, but it's only available in Australia.

I guess the question is why are you looking at Whey protein?

As a footnote, if you're in the UK, both the MyProtein Whey Isolate and Optimum Nutrition ones are low carb, while the Optimum Nutrition ones taste reasonably good too.