Girls who ate frequent meals and snacks put on fewer pounds and gained fewer inches to their waistlines over the next decade than those who only ate a couple of times each day, according to a new study.
Researchers said that one explanation is that smaller, more frequent meals and snacks kept girls satisfied for longer, and prevented them from over-eating.
But it's too early to say if that style of eating should be recommended to help prevent obesity in girls, or in the general population.
"Maybe if you eat smaller meals or you eat more frequently you're less likely to have a very large meal or be extremely hungry and over-eat at a meal," said Alison Field, who studies kids' eating at Children's Hospital Boston but didn't participate in the new research.
Still, "There's always the possibility... that people who decide to eat frequently are just inherently different people than people who just decide to eat a couple times a day," and that could explain changes in fat and weight gain in different girls, she told Reuters Health.
The new report, from Lorrene Ritchie at the University of California, Berkeley, is based on data from a government-funded study of black and white girls in Berkeley, Cincinnati and Washington, D.C.
Starting when girls were nine and 10 years old, they filled out food records of what they ate and when for a few days at a time and reviewed those records with nutritionists.
Over the next 10 years, researchers continued to track more than 2,100 girls' height, weight and waist size.
Ritchie used those records to compare the number of meals and snacks girls ate at the start of the study with changes in their weight and waist size through age 19 to 20.
Girls initially reported eating an average of about two and a half meals and another two and a half snacks each day.
As expected, no matter how frequently they ate, participants gained weight and waist inches over the study period as they went through puberty.
But the fewer snacks and meals girls ate during the day, the more fat they ended up putting on, Ritchie reported in the American Journal of Clinical Nutrition.
Over the ten years, those who started out eating more than six times a day climbed 6.5 points on the body mass index (BMI) scale, which is a measure of weight in relation to height. Girls that ate three times or less went up 7.8 points.
That works out to about eight extra pounds gained by the least-frequent eaters.
Girls who ate most frequently gained an average of four inches around their waists by the time they were 19 or 20, compared to almost five inches in girls with the fewest meal and snack times.
That was after taking into account other measures of health and lifestyle that could affect weight gain, including how often girls exercised or watched TV and how heavy they were to begin with.
MODERATION IS KEY
Ritchie said that some previous studies have linked more frequent snacks and meals with lower weight, but what's missing is research showing that if people change their diet habits to eat more often, they'll be able to shed pounds.
"The jury is still out," she told Reuters Health.
"I wouldn't recommend that people go out and say, 'Oh, I eat three meals a day and now I'm going to eat five to try to prevent weight gain,'" Ritchie said.
Moderation, she added, seems to be what matters.
"I would not skip meals as a way to prevent weight gain -- it doesn't seem be helpful, and I wouldn't necessarily avoid snacks."
Field pointed out that the study didn't take into account exactly what girls were eating at each snack and meal time -- and that could have an important effect on how much weight they ended up gaining and their overall health.
"If you're frequently eating but what you're eating is carrots and apples, that's really different than if you're frequently eating candy bars," she said.