A new study says Americans, after years of getting fatter and eating less healthy food, are consuming more fruits and vegetables and are beginning to lose weight.

Americans ate fresh fruit 6% more often and vegetables 5% more often last year than they did the year before, reversing a decline, according to a study of the eating patterns of 5,000 people over 14 days, conducted by market-research firm NPD Group Inc. Salad consumption at restaurants grew, driven in large part by a boom in salads offered at fast-food chains.

People also said they exercised more: Respondents who said they exercised strenuously at least once a week rose in 2003 to 66%, up from 63% the year before.

The percentage of those surveyed who said they are overweight or obese fell to 55% in 2003, down from 56% in 2002. Those numbers were based on respondents' self-reported height and weight and calculated by NPD using Centers for Disease Control and Prevention definition of Body Mass Index, or BMI.

"This is a shock to me," says Harry Balzer, a vice president at NPD and author of the study. "I've been watching the food industry for 25 years, and we've never seen America even hint at losing weight."

Americans still aren't eating as healthily as they did a decade go, according to NPD. For example, while Americans ate store-bought vegetables 127 times in 2003 -- six times as often as in 2002 -- that's still not as much as in 1993 when they ate vegetables 149 times.

NPD is a Port Washington, N.Y., market research firm that studies consumer trends in a variety of sectors ranging from food to cosmetics to apparel. Its clients are the companies in those industries who pay for NPD's syndicated data. NPD has conducted its Annual Eating Patterns in America study for 18 years.

Heightened awareness of the obesity problem may be playing a role. In late 2001, the Surgeon General issued a report warning that obesity rates in the U.S. reached "epidemic" levels and called for a "national plan of action." Since then, public-health officials, the U.S. government and media have strived to raise public awareness about Americans' bulging bodies. Some consumers have filed lawsuits against fast-food makers and food companies for allegedly contributing to obesity rates. This summer, the Food and Drug Administration ordered food companies to add a line to nutrition labels showing how many grams of artery-clogging trans fats are included in each serving by Jan. 1, 2006.

"With more and more of the population getting overweight, more people are getting concerned about their diet," says Kelly Brownell, director of the Yale Center for Eating and Weight Disorders, and an outspoken critic of the food industry. "The market for products with a healthy message attached would only grow in that environment."

All of this has huge implications for the food industry, which is scrambling to find products and marketing messages to lure consumers worried about obesity. A separate study from Information Resources Inc. shows sales of products whose name imply they offer healthier alternatives -- such as Weight Watchers, Lean Cuisine and Healthy Choice -- grew a combined 6.7% in 2002, in a sluggish food market.

After the success of low-fat sandwiches at Subway Restaurants, a unit of Doctor's Associates, burger chains Wendy's International Inc. and McDonald's Corp. recently rolled out tastier salads, which have fueled sales and brought in new customers. And just this month, Burger King Corp., owned by a group of private investors led by Texas Pacific Group, introduced three low-fat chicken sandwiches and a Lite Combo Meal featuring a low-fat sandwich, side salad and bottled water.

Write to Sarah Ellison at sarah.ellison@wsj.com³ and Shirley Leung at shirley.leung@wsj.com⁴