DENVER – Eating more frequently conferred less risk of excessive weight gain over the course of a decade among teenage girls participating in a large longitudinal study.
This finding lays the groundwork for intervention trials designed to learn whether changing eating frequency or the size of eating episodes alters obesity risk in young people, Lorrene D. Ritchie, Ph.D., observed at the annual meeting of the American Public Health Association.
She reported on 1,213 black and 1,166 white girls tracked prospectively from ages 9-10 years to 19-20 years in the National Heart, Lung, and Blood Institute (NHLBI) Growth and Health Study. Detailed 3-day diet record data were collected from participants on an annual basis.
Mean daily eating frequency during the 10-year study period was 2.57 meals and 1.67 snacks. A meal was defined as any eating episode involving consumption of at least 15% of total daily calories. All other eating episodes counted as snacks, explained Dr. Ritchie, director of research at the Atkins Center for Weight and Health at the University of California, Berkeley.
Eating frequency was greater when girls were younger, in whites as compared with blacks, and on weekdays rather than weekends.
Not surprisingly, the more times girls ate during the course of a day, the higher their caloric intake. But upon statistical adjustment for caloric intake, white girls who ate more frequently had significantly lower consumption of total fat, saturated fat, and sodium, and more intake of dietary fiber than did girls who ate less often. Among black teens the relationship was more variable.
For girls of both races, greater eating frequency – especially snacking – was paradoxically associated with significantly less 10-year gain in both body mass index and waist circumference after researchers adjusted for race, physical activity, hours of TV viewing, and parental education.
Few prior studies have investigated the relationship between frequency of eating and obesity in children. Two national cross-sectional studies found no relationship at all. One prior longitudinal study found an inverse relationship between eating frequency and adiposity, as seen in the NHLBI Growth and Health Study, but another longitudinal study showed a positive relationship between eating frequency and obesity. However, it’s tough to interpret the literature in this area because prior investigators used vague or inconsistent definitions of what constitutes meals and snacks. One strength of the Growth and Health Study is that it used objective definitions, Dr. Ritchie noted.
Her analysis was supported by a grant from the U.S. Department of Agriculture. She declared having no relevant financial relationships.