Overweight adults eat less often than people in the normal body weight range, but still take in more calories and are less active over the course of the day, according to a U.S. study.
By contrast, normal weight adults, including those who had lost a lot of weight and kept it off, ate more often, according to findings published in the Journal of the American Dietetic Association.
“Most of the research has shown that people who eat more frequently have a lower weight. But no one knows why,” said lead researcher Jessica Bachman, an assistant professor in the department of Nutrition and Dietetics at Marywood University in Scranton, Pennsylvania.
More than 60 percent of U.S. residents are obese or overweight, but the relationship between the number of meals people eat each day and the ability to maintain weight loss has remained unclear, she said.
In particular, she wanted to understand what people who have lost significant amounts of weight do to keep it off.
Bachman and her team followed about 250 people for a year, analyzing data collected in two large studies sponsored by the National Institutes of Health.
One looked at the eating habits of people with a body mass index - BMI, a measure of weight relative to height - between 25 to 47, which is considered overweight to obese.
The other study looked at adult men and women who were normal weight, with a BMI of 19-24.9, about half of whom had lost at least 13.6 kg (30 lbs) and maintained their lower weight for more than five years.
Obesity is common, serious and costly
- About one-third of U.S. adults (33.8%) are obese.
- No state has met the nation’s Healthy People 2010External Web Site Icon goal to lower obesity prevalence to 15%. The number of states with an obesity prevalence of 30% or more has increased to 12 states in 2010. In 2009, nine states had obesity rates of 30% or more. [See maps ] In 2000, no state had an obesity prevalence of 30% or more.
- Obesity-related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer, some of the leading causes of death.
- In 2008, medical costs associated with obesity were estimated at $147 billion; the medical costs paid by third-party payors for people who are obese were $1,429 higher than those of normal weight.
Obesity prevalence varies across states and regions
- By state, obesity prevalence, on the basis of self-report, ranged from 21% in Colorado to 34% in Mississippi in 2010. Twelve states had a prevalence of 30% or more.
- The South has the highest obesity prevalence (29.4%) followed by the Midwest (28.7%), Northeast (24.9%) and the West (24.1%).
On average, the normal weight subjects ate three meals and a little over two snacks each day, whereas the overweight group averaged three meals and just over one snack a day.
Generally, though, weight loss “maintainers” consumed the fewest calories, at about 1,800 a day, compared with the normal weight and overweight subjects, who took in 1,900 and more than 2,000 calories a day, respectively.
Bachman said that snacking might help prevent weight gain by staving off intense hunger.
“If you eat more often, it stops you from getting too hungry. If you wait 10 hours after you’ve last eaten, you end up eating a lot more food,” she added.
She noted that weight loss maintainers were also the most physically active, burning off about 3,000 calories a week through exercise and other activities, compared to 2,000 calories a week among the normal weight subjects and 800 calories a week in the overweight group.
“It appears that being extremely physically active and eating more often helps them keep the weight off,” she said, adding that more research is needed.