Child Body Mass Index and the Family Obesogenic Environment in a Sample of Children Adopted at Birth

• Published in: Obesity (Silver Spring, Md.) Vol. 29; pp. 72 - 73
• Main Authors: Robertson, Olivia, Marceau, Kristine, Natsuaki, Misaki, Shaw, Daniel, Reiss, David, Leve, Leslie, Neiderhiser, Jenae, Ganiban, Jody
• Format: Journal Article
• Language: English
• Published: Silver Spring Blackwell Publishing Ltd 01.12.2021
• Subjects: Body mass index; Children & youth; Families & family life; Girls; Obesity
• ISSN: 1930-7381; 1930-739X

Background: Childhood obesity is genetically and environmentally influenced, including the family environment (Silventoinen et al., 2010). Most investigations of obesogenic family environments have studied families where parents raise their biological children, which confounds environmental risk factors with heritable risk for obesity or gene environment correlation (rGE). Additionally, gene by environment interaction (GxE) studies suggest that heritable risk for obesity may be more strongly associated with childhood BMI in highly obesogenic environments (Schrempft et al., 2018). We tested GxE while controlling for rGE using an adopted at birth design. Methods: Using cohort I (n = 361) of the Early Growth and Development Study, a US-based sample of children adopted into non-relative families at birth, we examined whether the obesogenic family environment moderated heritable influences (birth parent BMI) for higher BMI in 4-7 year old boys and girls. The obesogenic family environment was typified by latent profiles derived from indicators of adoptive parent characteristics, feeding behavior, and parenting. We interpreted three profiles; average (n = 276): all indicators close to the sample average; weight concerned (n = 52): above average scores on concern for child's weight, slightly elevated food monitoring and restriction, and slightly reduced pressure to eat; and low food control (n = 31): lower scores on food monitoring and restriction. Results: In boys and girls, membership in the weight concerned group was associated with higher child BMI than the average and low control group. Additionally, there was evidence of GxE, such that the association between genetic influences and child BMI was stronger in the weight concerned compared to the average group in girls and boys. For girls, the association between heritable influences and child BMI was positive (predicting higher BMI), whereas for boys the association was negative. Conclusions: The family obesogenic environment predicts child BMI after accounting for heritable risk, and patterns of GxE may be sex specific.