MONDAY, April 8, 2013 (HealthDay News) -- In what may seem a surprising finding, kids in a new study who ate more often over the course of a day were less likely to be overweight than their peers who ate the traditional three squares.
Looking at 11 past studies, Greek researchers found that overall, kids -- particularly boys -- who typically dined more than three times a day weighed less than those who had three or fewer meals. And they were 22 percent less likely to be overweight or obese.
The findings, reported online April 8 and in the May print issue of Pediatrics, are in line with the theory that smaller meals, spaced out over the day, may aid weight control.
The big caveat, however, is that the findings do not prove cause and effect, said Alison Field, an associate professor of pediatrics at Harvard Medical School and a staff scientist at Boston Children's Hospital.
Field, who was not involved in the research, said the main issue is that all 11 studies were conducted at just one point in time. So it's impossible to know whether the children's eating habits came before their extra pounds. Some kids may have started eating less often after becoming overweight.
You need studies where kids are followed over time to know which came first, Field said. And even then, it can be hard to disentangle whether it's the eating frequency that matters.
"People who eat frequently may choose different foods compared with people who eat less often," Field said. "Is it the eating frequency, or what you're eating?"
Registered dietitian Connie Diekman agreed that the study "does not provide conclusive evidence." Still, other studies have suggested that smaller, more frequent meals may help control weight gain, according to Diekman, director of university nutrition at Washington University in St. Louis.
"I view this study as one more piece in our understanding about meal frequency and weight, but not of itself an answer to, what do we tell consumers?" said Diekman, who did not work on the study.
For the review, Panagiota Kaisari and colleagues at Harokopio University in Athens combined the results of 11 studies involving nearly 19,000 kids aged 2 to 19. The studies typically compared kids who ate more than three meals per day with those who ate less often. Some studies counted snacks as "meals," while others did not.
With all the findings combined, kids who ate more often were less likely to be overweight. When the researchers took a closer look, though, the link seemed to hold true only for boys, and not girls.
It's not clear why girls and boys differed, according to Kaisari's team. And there could be other reasons that boys who eat frequently weigh less.
Some of the studies tried to account for those factors, such as exercise habits. But the studies varied in which factors they considered, and that's a limitation, Kaisari's team noted.
"This all raises more questions than answers," Field said.
It is biologically plausible that eating frequency affects metabolism and weight control, according to Field. And other studies, she said, have suggested that skipping breakfast is associated with weight gain -- though it's not clear why that is.
What is clear, according to Field, is that what your child eats, and how many total calories he or she gets, is key. "If you're eating frequently, but you're eating fast food, that's obviously not good," she said.
And if your child is currently eating three big meals, this study does not imply you should add snacks to that, Field stressed. "What you don't want parents to do," she said, "is add calories to what their child is already eating."
The Academy of Nutrition and Dietetics has advice on healthy eating for kids.