Multi-behavioral obesogenic phenotypes among school-aged boys and girls along the birth weight continuum.
In plain language
Birth weight, eating and activity do not follow one simple pattern
Both low and high birth weight have been associated with later excess body fat. Could eating, activity and sleep help explain why opposite ends of the birth-weight range sometimes lead to similar health outcomes? This study examined that question across the full range of birth weights rather than comparing only small and average-sized babies.
Looking for curves as well as straight lines. Parents of 460 Montreal children aged six to twelve reported birth information, body measurements, sleep, screen time, physical activity and eating behaviors. Birth weight was expressed relative to the expected weight for the child’s sex and gestational age. The researchers examined boys and girls separately and allowed the associations to be curved. A U-shaped relationship means that a measure is higher at both extremes than in the middle; an inverted U means the reverse.
Different behaviors showed different relationships. In boys, both physical activity and screen time had U-shaped associations with birth weight. In girls, physical activity showed an inverted U. Emotional eating and restrained eating increased with birth weight in both sexes. Sleep duration and eating in response to external food cues were not associated with birth weight.
Body mass index also followed a U-shaped pattern in boys, but no comparable association was found in girls. Sleep was related to BMI in both sexes, while eating-related associations were found in girls. An exploratory analysis suggested that emotional eating might account for part of the relationship between birth weight and BMI in girls. Because these measures were collected at the same stage, this statistical mediation cannot establish the sequence of cause and effect. The results did not provide one behavioral explanation across both sexes.
The study’s contribution is to show the variety hidden by a simple claim that children born small or large have one common set of obesity-related behaviors. Associations differed by behavior and sex, and more activity could coexist with more screen time. Understanding developmental pathways to body weight requires following these patterns over time and testing which ones actually contribute to later weight gain.
Original abstract
Evidence shows that extremes of birth weight (BW) carry a common increased risk for the development of adiposity and related cardiovascular diseases, but little is known about the role of obesogenic behaviors in this process. Moreover, no one has empirically examined whether the relationship between BW, obesogenic behaviors and BMI along the full low-to-high birthweight continuum reflects the U-shape pattern expected from common risk at both BW extremes. Our objective was to characterize physical activity, screen time, and eating behavior and their relationship to BMI as a function of BW among school-aged boys and girls. In this cross-sectional study, 460 children aged 6 to 12 years (50% boys) from Montreal, Canada provided information on sleeping time, screen time, physical activity levels, eating behavior (emotional, external and restrained eating) and anthropometrics (height, weight, BW) through parent reported questionnaires. BMI was normalized using WHO Standards (zBMI), and BW expressed as ratio using Canadian population standards (BW for gestational age and sex). Analyses were conducted using generalized linear models with linear and quadratic terms for BW, stratified by sex and adjusted for age, ethnicity and household income. In boys, physical activity and screen time showed U-shaped associations with BW, while physical activity had an inverted U-shaped in girls. Emotional and restrained eating had positive linear relations with BW in boys and girls. Sleep time and external eating were not associated with BW. A U-shaped relationship between BW and zBMI was found in boys but no association was found in girls. Only sleep (in boys and girls), and emotional eating (girls only) were related to zBMI and mediation of the BW-zBMI relationship was only supported for emotional eating. In conclusion, BW relates to obesogenic behaviors and BMI in both non-linear and linear ways, and these associations differed by sex.
Reproduced from the original publication under CC BY 4.0. Wording unchanged; layout and typography normalized.
Portella AK, Paquet C, Bischoff AR, Molle RD, Faber A, Moore S, Arora N, Levitan R, Silveira PP, Dube L. Multi-behavioral obesogenic phenotypes among school-aged boys and girls along the birth weight continuum. PloS one. 2019;14(2):e0212290.
Read the original publication and abstract