Frozen pizza and snacks was the strongest private label growth category during a 52-week period ending July 11, 2009, according to The Nielsen Company. Nielsen, Chicago, said the frozen private label pizza and snacks segment posted a 38 percent dollar sales increase and a 22 percent unit sales increase compared to a year before.

In its latest report, "U.S. Store Brand Development," Nielsen said total sales of all private label products grew 7.4 percent to $85.9 billion during the same 52-week period. Unit sales also rose 5 percent to 39.5 billion units during the same tracking period. Data include sales from all food, drug and mass merchandisers including Wal-Mart.

Nielsen said all store brand food and non-food categories experienced better performance versus brands, but edible departments saw the greatest uptick in dollar and unit sales.

"When categories are sorted by store brand share -- from high to low -- some patterns emerge," noted Todd Hale, senior vice president, Consumer & Shopper Insights at Nielsen. "Store brand performance and share is strongest in commodity categories. . . . Where store brand share is lowest is among categories where we see strong marketing support for top brands including candy, gum, beer and those where a high level of innovation occurs, like detergents, deodorant and cosmetics."