One talking point that emerged from Kraft Heinz's approach for Unilever was the companies' approaches when it comes to corporate responsibility and sustainability. Unilever is seen as being in the vanguard of developing a sustainable business; Kraft Heinz, with its emphasis on cost control and margin improvement, less so. But how far do investors care? In a guest column, Ravi Varghese of US sustainability non-profit Ceres challenges mainstream investor thinking that sustainability is a drag on efficiency.