The latest proposed changes by companies might be, in part, a reaction to increased attention to the epidemic of overweight and obesity and, in part, a reaction to recent obesity-related lawsuits. Various companies have been threatened with suits by consumers claiming that their fat- and calorie-rich foods have caused them or their children to become overweight.

But not everyone believes that the food manufacturers should be held responsible. In June, the National Restaurant Association supported efforts by U.S. Rep. Ric Keller of Florida to try to pass the House bill "Personal Responsibility in Food Consumption Act" in Congress. The bill would protect restaurants, as well as food and beverage makers, from being sued by overweight and obese consumers.

One New York lawmaker recently proposed a 1% so-called "fat tax" on junk food, video games and video game equipment, and TV commercials to raise funds to help combat rising obesity rates.

Whether the food companies are ultimately held responsible or not, many are applauding Kraft's plans to develop smaller portion sizes and improve the nutritional content of their foods. "I think it could help," says Jessica R. Donze, RD, CDE, a pediatric nutrition therapist in Virginia. "Cultural change would be of great help and culture can be altered for better or worse via marketing."

Still, nutrition experts acknowledge that a major shift in consumers' buying and eating habits could take quite a while. "These changes are going in the right direction, but I think if there is the expectation of rapid radical change, they don't know human nature," says Sandra G. Hassink, MD, director of the weight management program at a children's hospital in Delaware.