Abstract

Obesity is a major public health problem in Peru. Cohabiting couples may show obesity clustering because of partner selection, shared household routines, and broader structural exposures. This study aimed to describe spousal similarity in body mass index (BMI) and obesity status among DHS-eligible male-headed cohabiting couples in Peru and to examine variation across sociodemographic subgroups. We conducted a cross-sectional analysis of DHS 2019 and 2021–2024, excluding 2020. The study included heterosexual cohabiting couples in which the man was the household head aged ≥ 18 years and the woman was the spouse/partner aged 15–49 years, with anthropometric measurements available for both. BMI was calculated from measured weight and height; obesity was defined as BMI ≥ 30 kg/m2. We accounted for the complex survey design and used Pearson correlations, weighted kappa statistics, and Poisson regression with robust variance to estimate crude and exploratory adjusted prevalence ratios (PRs) for obesity clustering. The final analytic sample included 27,604 couples. Obesity prevalence was 25.8% in husbands and 33.3% in wives. Overall, 52.1% of couples had neither spouse with obesity, 14.5% had only the husband with obesity, 22.0% had only the wife with obesity, and 11.3% had obesity in both spouses. BMI correlation between spouses was r = 0.19 (95% CI: 0.18–0.21), the weighted kappa for BMI categories was 0.17, and the crude PR for wife obesity given husband obesity was 1.47 (95% CI: 1.39–1.56). In exploratory adjusted models, the PR for wife obesity given husband obesity was 1.34 (95% CI: 1.26–1.41), and the reverse PR for husband obesity given wife obesity was 1.39 (95% CI: 1.31–1.49). Observed concordance was somewhat stronger in urban, coastal, and wealthier subgroups but remained modest overall. Among DHS-eligible heterosexual cohabiting couples in Peru, restricted to male household heads and female spouses/partners aged 15–49 years, obesity showed positive but modest spousal concordance. These findings support cautious incorporation of couple-level perspectives into obesity surveillance and future research, but they do not establish causal mechanisms or demonstrate the effectiveness of couple-based screening or interventions.

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