The eating habits of American children appear to be shifting. And for a change, the news is good.

Chicken nuggets, burgers, fries and colas remain popular with the under-13 set, of course. But new market research shows that consumption of these foods at restaurants is declining, while soup, yogurt, fruit, grilled chicken and chocolate milk are on the rise.

The findings, based on survey data by the Chicago market research firm NPD Group, follow a report last year that childhood obesity appears to have hit a plateau after rising for more than two decades. That finding, reported by The Journal of the American Medical Association, has been greeted with guarded optimism, and it remains unclear whether efforts to limit junk food and increase physical activity in schools have had a meaningful effect on the way children eat.

But the new data suggest that a number of factors, from the economic downturn to new offerings from fast-food giants, may be influencing a general shift in eating preferences among children.

The data, from NPD’s Consumer Reports on Eating Share Trends, are collected from a representative sample of 3,500 households and 500 teenagers who give detailed information on their restaurant habits. The figures are considered highly reliable because the researchers collect answers daily, asking participants what they and their family ate and ordered at restaurants the day before. While this recall method is never 100 percent reliable, the data, collected since 1976, provide a consistent look at long-term trends.