According to the University of Michigan's American Customer Satisfaction Index, Kellogg and Sara Lee have improved their customer satisfaction this year, while food industry leader HJ Heinz has seen its score drop to the lowest level in seven years, making for tight competition at the top.

The survey, which scores food and beverage brands each year, found that overall satisfaction with food manufacturers rose 1.2% to an index score of 83, the industry's highest score in 10 years.

Kellogg and Sara Lee each rose 5% to a score of 85. Sara Lee increased consumer satisfaction by sharpening its focus on its core business, shedding less successful product lines including peripheral brands and launching its first-ever umbrella image campaign, "The Joy of Eating." Meanwhile Kellogg's health-awareness marketing and new health-oriented products, such as Special K-branded water and snack bars, boosted its performance, researchers said.

Meanwhile, Heinz, dropped 4.4% to a score of 87, its worst showing since 1999. The ketchup maker still tops the list of food manufacturers in terms of customer satisfaction, but is just above Hershey, Kraft Foods and Mars, all of whom have a score of 86.