A stylish friend of mine from Malibu, who oozes the latest liberal cause célèbre and fashion from every pore, recently complained to me that it was becoming extremely difficult to throw dinner parties in Los Angeles. She explained that it was now commonplace for friends and acquaintances invited for a meal to have their secretaries send over an advance warning of things they could not, or would not, eat. Not confined to the usual allergies or religious requirements, guests were vetoing red meat, ruling out carbs, or demanding oily fish to fit in with their latest health obsession. The final straw for her was when some old friends had their office telephone to say they were only eating white food this week and could she please adjust the menu. The temptation to serve up tripe must have been overwhelming.