At Temple lab, a child's-eye view of how to eat

Want your children to eat less?

Let them serve themselves. They probably won't dole out a supersize portion on their own.

Or pour drinks into tall, narrow glasses rather than short, wide ones; they'll think they are getting more (so will you).

With Americans spending billions of dollars a year on fat-loss techniques ranging from celebrity diets to stomach-stapling surgery, the relatively new field of behavioral nutrition examines more down-to-earth questions.

Can you reduce the attraction of sweets? Can you supersize fruits and vegetables? (Yes in both cases, although it depends on the child.)

"It's a matter of asking: What are children experiencing and how are those experiences shaping their eating?" said behavioral nutritionist Jennifer Orlet Fisher, an associate professor in Temple University's Department of Public Health.

Among the huge army of scientists attacking the obesity epidemic, Fisher occupies a narrow field: how children's eating behaviors are influenced by their early family environment and, for her current research, portion sizes.

If that sounds mundane, consider this: Obesity is among the most serious threats to Americans' health, with rates of obese and overweight children tripling since the 1960s. The cause is mostly too many calories going in and too few going out. The solution is largely getting people to eat less and exercise more.

Almost nothing has worked.

"Portion control," said Hollie Raynor, an associate professor of nutrition at the University of Tennessee, "is considered to be one of the large contributing factors to overeating."

Fisher, who is trained in nutrition with an appreciation for developmental psychology, often gets ideas for research in her own kitchen while trying to satisfy 5-year-old twins Theo ("the adventurous eater") and Ian ("the cautious eater").

She gathers hard data in her Family Eating Laboratory at Temple, where eating can be measured, videotaped, and manipulated under tightly controlled conditions.

On a recent evening, three children sat in little plastic chairs at a table in a room with lions and giraffes painted on the walls. When an assistant said "go," they served themselves pizza - their choice of zero, one, or two 3.5-by-4.5-inch pieces weighing a total of 7.94 ounces.