Should be fine, I have a really low appetite so my doctor suggested smoothies with protein powder so I can get more nutrients.

I'm not a doc, I do have my condition of epilepsy and do take different things as food and such, I think it's different per person, what effects me may effect the individual differently, does the person who you are talking about have a doc or physician, I would suggest bringing that up and ask, not that asking here doesn't, but just to be safe and get your opinion and options and go from there, . my opinion to the question here.