The causal effect of number of children on later-life overweight and obesity in parous women. An instrumental variable study

Abstract

Many older women in Europe are overweight or obese. One of the factors linked to overweight and obesity among older women is childbearing. However, results of observational studies on the association between women’s number of children and excess weight should be interpreted with caution, because they may be prone to bias due to residual confounders or reverse causation. We use data of women aged 50 and older with at least two births from seven waves the Survey of Health, Ageing and Retirement in Europe (n = 113,932) collected between 2004 and 2020. We adopt an instrumental variable approach that exploits the well-established preference for mixed-sex offspring to estimate the causal effect of number of children on older parous women’s body mass index (BMI) and their risk of overweight (BMI >= 25 kg/m2) and obesity (BMI >= 30 kg/m2). The instrumental variable models provided evidence for a causal positive effect of having 3 + children as opposed to 2 children on mothers’ body mass index, overweight (BMI >= 25 kg/m2) risk and obesity (BMI >= 30 kg/m2) risk. Predicted BMI was 1.8 kg/m2 higher for mothers with 3 + children than for mothers with 2 children, and their predicted probability of overweight and obesity was 18.3 and 8.6 percentage points higher, respectively. Results remained virtually unchanged after adjusting for age, educational attainment, country and wave of data collection.

Longitudinal health behaviour patterns among adults aged ≥50 years in China and their associations with trajectories of depressive symptoms

“…Wave numbers were deducted with one, so that the intercepts in the estimated models of depressive symptoms can be interpreted more intuitively. Given their known associations with health behaviours (Feng et al, 2021;Grundy & Read, 2015;Margolis, 2013;Van den Broek, 2021a;Van den Broek & Fleischmann, 2021) as well as with mental health (Chen et al, 2017;Feng et al, 2019;Grundy et al, 2019;Read et al, 2016;Van den Broek, 2021b;Zhai et al, 2015), age, gender, level of urbanization of location of residence, level of education, marital status, number of children, and co-residence with a child were moreover considered as potential confounders. Time-invariant covariates were gender (male/female), age at baseline in years (centred on the sample mean), educational attainment (at least upper secondary education/lower secondary education or lower]), level of urbanization of location of residence (urban/rural) and number of living children (0/1/2/3/≥4).Time-varying covariates were co-residence with at least one child (no/yes) and partner status (not partnered [separated, divorced, widowed, or never married]/partnered [currently married or cohabiting]).An overview of sample characteristics is provided in Table 1.…”

Role of child marriage on women’s nutritional status in adulthood

“…There could be multiple pathways of the relationship between child marriage and women's nutritional status in later life, entailing various biological and behavioral attributes. Child marriage is associated with higher lifetime fertility and early childbearing, both of which can increase the risk of obesity in women [18,19]. Lower SES conditions associated with child marriage may also impact BMI-based nutritional status through health-promotion (e.g., physical exercise) and health-risk (e.g., unhealthy diet) behaviors.…”

Gender differences in bodyweight change following COVID-19 lockdown measures in the Netherlands: a prospective longitudinal study

“…Our outcome of interest is self-reported bodyweight in kilograms. Consistent with earlier studies,29 30 we considered values below 25 kg implausibly low and excluded observations with such values (n=122) from our sample.…”