In 2000, Kellogg moved to buy US group Kashi in a bid to expand into growing parts of the country's cereal category and help efforts in what the Special K maker called at the time "the rapidly growing natural foods marketplace". However, 15 years on, the acquisition can be held up as an example of how a food major buying an up-and-coming, fast-growing rival can go wrong. Kashi has struggled for growth in recent years but, speaking at this week's Consumer Analyst Group of New York conference this week, Kellogg set out its plans to revitalise the business.