Overweight Adolescents Eat Less Than Healthy-Weight Peers

Emma Hitt, PhD

September 10, 2012

September 10, 2012 — Obese and overweight adolescents consume fewer calories than their age-matched healthy-weight peers, according to the findings of a nationally representative cross-sectional sample. In contrast, younger obese and overweight children consume significantly more calories than their peers.

Asheley Cockrell Skinner, PhD, from the University of North Carolina at Chapel Hill, and colleagues reported their findings in an article published online September 10 in Pediatrics.

According to the researchers, previous research has shown inconsistencies in the association between energy intake and obesity. In the current study, the authors hypothesize that "[v]ariation in energy intake by weight status at different ages may explain inconsistencies in previous research on energy intake and obesity." They therefore examined the relationship between reported daily energy intake and categorized weight status across childhood.

Dr. Skinner and colleagues analyzed dietary reports of children aged 1 to 17 years, collected for the National Health and Nutrition Examination Survey, 2001 to 2008 (n = 12,648). Current recommendations were used to categorize weight status into obese, overweight, or healthy weight according to weight-for-length percentile (age < 2 years) or body mass index percentile (ages 2 - 17 years). Dietary intake was reported by the validated automated multiple-pass method (a detailed 2-day 24-hour recall).

In girls aged 1 to 8 years, there was a nonsignificant trend for very obese, obese, and overweight children to have increased energy intake compared with healthy-weight or underweight children of the same age. The findings were similar in boys, and the differences were strong enough to reach statistical significance for boys aged 6 to 8 years, the researchers note.

In contrast, beginning at age 9 to 11 years for girls and boys, children who were a healthy weight had greater energy intake than children who were very obese, obese, or overweight, a pattern that was significant for girls and older boys.

The findings, according to the researchers, suggest that differences in energy intake by weight status are dependent on age. However, they add that they "would expect, based on conventional understanding, that overweight and obese children would consume more calories than healthy-weight children."

They suggest that they finding could be explained by the fact that increased energy intake in earlier childhood leads to the onset of obesity, and that this becomes "self-perpetuating."

"If a child has a balance of energy consumed versus expended, an overweight child will tend to remain overweight while a healthy-weight child will remain healthy weight," Dr. Skinner and colleagues said.

"It makes sense for early childhood interventions to focus specifically on caloric intake, while for those in later childhood or adolescence the focus should instead be on increasing physical activity, since overweight children tend to be less active," Dr. Skinner noted in a university news release.

This study was supported by the University of North Carolina. Dr. Skinner is currently supported by Building Interdisciplinary Research Careers in Women's Health. One coauthor is supported by a career development award from the National Institutes of Health. The authors have disclosed no other relevant financial relationships.

Pediatrics. Published online September 10, 2012. Abstract