Inflammation, in turn, has been linked in previous studies with a higher risk of developing type 2 diabetes and heart disease.
"At bedtime, when we compared the obese women with the lean women, the obese women had higher endotoxins after the five-meal day," Piya said. That would, he said, theoretically, boost their risk of diabetes and heart disease. "The lean women did not have higher endotoxins when they had five meals compared to two."
The new findings make sense to Michelle Kulovitz Alencar, an assistant professor of kinesiology at California State University, San Bernardino. "In my own research, I have found that it's all about calorie intake," she said, not how the calories are spread out during the day, for weight loss results.
In studies Alencar has done comparing different meal frequencies, she finds those who eat more meals tend to underreport what they actually eat.
Recently, she reviewed published studies on how meal frequency might affect weight loss. That report is published in the April issue of the journal Nutrition.
Researchers remain uncertain about the best meal frequency for weight loss, Alencar said. However, some research suggests fewer meals per day may help obese people control cholesterol better, she noted.
Alencar agreed with Piya, however, that for now people should stick with the approach they are used to. She suspects that those who switch their patterns -- going from three meals a day to five, or the reverse -- may ''throw off'' their hunger hormones, making them feel hungrier in some cases.
For now, Alencar said: "Stick with what you know and reduce calories."
Piya can't say if the findings apply to men. "There are no obvious reasons that we would expect men to respond differently, but obviously we are unable to draw conclusions about men until we [do] studies in men," he said.
Because the new study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.