Obese kids eat 34 percent more calories from snacks, finds recent study. That can be enough calories, if sustained over time, to continue excess weight gain.
In a study of 47 same-sex sibling pairs, the research by University of Pennsylvania School of Nursing showed that even after eating a meal they enjoyed until they were full, overweight and obese children were more prone to overeating when presented with desirable snack foods than their normal-weight siblings.
The study also showed that normal-weight siblings ate less of the meal than their overweight siblings, when provided with a calorie-dense appetizer just before the meal.
"The overweight and obese siblings showed an impaired ability to adjust for calorie differences and consumed more snacks even when satiated," lead author Tanja Kral, PhD, an assistant professor at Penn Nursing, said.
"These findings suggest some children are less responsive to their internal cues of hunger and fullness and will continue eating even when full," Kral added.
This inability may be inherited and exacerbated by an environment that offers large portions of desirable foods, Dr. Kral said, explaining that the full siblings in the study were more similar in their eating behaviors more commonly ate more than the half-siblings, suggesting a genetic influence underlying these traits.
In the study, siblings ate a standardized dinner of pasta with tomato sauce, broccoli, unsweetened applesauce, and two percent milk once a week for three weeks.
When presented with desirable post-meal snack foods, the overweight and obese siblings ate an average of 93 calories more than their normal-weight siblings.
This additional calorie intake over time is considered enough to lead to excess weight gain.
"These findings may represent a behavioral inclination for obesity in children," Dr. Kral said.
The study is published in The American Journal of Clinical Nutrition.