In 1998, the Centers for Disease Control and Prevention estimated, 22 percent of children under 5 were overweight. Overweight children can have high blood pressure, sleep problems, and psychological and social problems. Part of this is probably because of diet, and researchers at Pennsylvania State University and the University of North Carolina looked at how young children's diet has changed since the 1970s.

What the researchers wanted to know: Are preschoolers eating better than they were in 1977?

What they did: The researchers used data from three surveys administered between 1977 and 1998, which covered the diets of about 8,600 2- to 5-year-olds (no, they didn't describe their own diets; the interviewers asked someone else in the house what the kids were eating).

What they found: Kids are eating more sugary foods and drinking more juice (which can be unhealthy when it's not drunk in moderation) than they were in 1977. And while they're eating more grains, fruit, vegetables, and dairy products—good—they're also eating more overall—not so good.

What the study means to you: Yep: Preschoolers are eating more sugary foods. Other studies have shown that being overweight and having poor eating habits tend to last.

Caveats: The adults who reported on the children's diet might not have known everything the kids were eating. Also, the surveys conducted in different years weren't exactly the same, although the researchers did come up with a system to link the answers.

Find out more: Principles for feeding your 4- to 5-year-old: http://www.lpch.org

Read the article: Kranz, S., Siega-Riz, A.M. and A.H. Herring. "Changes in Diet Quality of American Preschoolers Between 1977 and 1998." American Journal of Public Health. September 2004, Vol. 94, No. 9, pp. 1525-1530.

Abstract online: http://www.ajph.org