PepsiCo, Coca-Cola and McDonald's aren't the only corporate giants vying to make themselves over as promoters of good health and fitness. General Mills, the maker of a full line of cereals including such sugary products as Trix, Lucky Charms and Cocoa Puffs, has launched a campaign promoting children's nutrition. General Mills's non-branded TV spots encourage kids to "think fast," "get going" and "have power" by eating a nutritious breakfast. "We want kids to understand the importance of having breakfast in the morning," said Marybeth Thorsgaard, a company spokeswoman.

But not everyone is swallowing it. "Who are they trying to kid?" asked Bonnie Liebman, director of nutrition at the Center for Science in the Public Interest, who termed many ready-to-eat cereals "breakfast candy." "This is an attempt to get good PR," she said.

Healthy Start? General Mills drew praise from experts -- including Liebman -- for stressing the importance of eating whole grains when the company reformulated its cereals this year to include them. However, labels don't specify how much of those whole grains you're getting. And some products remain low in fiber: Whole Grain Lucky Charms contains one gram per serving. The company also reduced the sugar in several kid-targeted brands. But nutritionists at five universities recently found the lower-sugar varieties -- from multiple manufacturers, not just General Mills -- no more healthful, because the sugar has been replaced with other refined carbohydrates.

Sweet Deal General Mills cites studies showing that a healthful breakfast -- including sweetened cereals -- helps boost children's test scores and reduce discipline problems at school. The company further claims that eating cereal for breakfast has a healthy impact on body weight. There, the data are less convincing. In May, the Journal of the American Dietetic Association published an analysis of 47 studies on eating breakfast. Of the 16 that looked at body weight, only two reported an association -- not a cause-and-effect relationship -- between eating pre-sweetened cereal and having a healthy body weight.

-- Susan P. Williams