What’s a good breakfast for growing children? Ask Penn Nursing professor Tanja Kral and she’ll likely answer, “One that incorporates protein-rich foods like eggs.”

Based on a recent study Kral conducted with colleagues from the University of Massachusetts and Emory University, a protein-rich breakfast fills children’s bellies longer than cereal or oatmeal, which causes them to eat a smaller lunch.

Though the effect doesn’t last for the entire day, a protein-rich breakfast does lead to consuming fewer calories during the midday meal.

“After consuming the egg breakfast”—which comprised of scrambled eggs, whole wheat toast, diced peaches, and 1 percent milk—“children reduced their energy intake at lunch by 70 calories,” Kral says. That’s roughly equivalent to one small chocolate-chip cookie.

“We didn’t see this reduction after the cereal or oatmeal breakfast,” she adds.

Seventy calories may not sound significant, but according to the U.S. Department of Agriculture, moderately active 8- to 10-year-old children need between 1,600 and 1,800 calories daily. The 70-calorie drop at one meal equals about 4 percent of a child’s daily caloric needs. Eating beyond the caloric threshold, even by a little, can cause excess weight gain and obesity, if sustained.

To determine their findings, the researchers recruited 40 8- to 10-year-old children to come to the Center for Weight and Eating Disorders at Penn once a week for three consecutive weeks. At each visit, the children consumed one of three 350-calorie breakfast options, played games with research staff, then ate lunch. The study was recently published in the journal Eating Behaviors.

Every participant had to eat their entire breakfast, but could eat as little or as much lunch as desired. They also answered appetite-rating questions like, “How hungry are you?” and “How much food do you think you could eat right now?” Their parents logged in a food journal what the children ate the remainder of the day.

Kral says she was not surprised that the egg breakfast kept children full the longest. What did surprise her, however, was the fact that, according to the children’s reports, eating the egg breakfast didn’t make them feel fuller than the cereal or oatmeal breakfast even though they ate less for lunch.

Though Kral says future research should study children over a longer period of time, these findings could have important implications for obesity, particularly for young people at greater risk for the disease.

“Approximately 17 percent of children and adolescents are considered obese in the United States,” Kral says. “It’s really important to identify certain types of food that can help children feel full and also moderate caloric intake.”