Food snobs may sneer but McDonald’s is the biggest fast food business in the world because it serves up affordable treats people like to eat. Devotees of DIY healthy cooking at home may wish it weren’t so but McDonald’s is also a major beneficiary of the long-term trend toward eating out. Rising numbers of people around the world, in developed and emerging economies, are ‘cash rich but time poor’ and one thing they all have in common is getting hungry.