The performance of the UK food retail sector over Christmas came under scrutiny this week and there were some clear winners and losers. Elsewhere, the M&A rumour mill continued to turn, with German yoghurt giant Müller in talks to buy UK milk supplier Robert Wiseman Dairies. In the US, baker Hostess Brands applied for Chapter 11 protection for a second time, Cargill reported its worst quarter in a decade and Archer Daniels Midland announced a swathe of job cuts. On just-food's insight pages, we looked at Bi-Lo's plan to buy fellow UK retailer Winn-Dixie and at the importance of price optimisation.