Sales of cottage cheese are booming thanks to a boost from protein-hungry social media influencers. But do we really need all this extra protein? Madeleine Finlay speaks to Joanne Slavin, a professor of food science and nutrition at the University of Minnesota, to find out what exactly protein is doing in our bodies, and what happens to it when we consume it in excess. Help support our independent journalism at theguardian.com/sciencepod