War in the Middle East is pushing up the cost of fuel, fertiliser and freight and it could affect everything from bread, pasta and cereals. Hannah Twiggs explains what that means for the price of your weekly shop and whether stocking up now makes sense A few weeks ago, the question was whether war in the Gulf might affect the British weekly shop. Now, that question is no longer theoretical. The effects are already beginning to feed into the system. Central banks, supermarkets and manufacturers