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Social connections and the healthfulness of food choices in an employee population


Unhealthy food choice is an important driver of obesity, but research examining the relationship of food choices and social influence has been limited. We sought to assess associations in the healthfulness of workplace food choices among a large population of diverse employees whose food-related social connections were identified using passively collected data in a validated model. Data were drawn from 3 million encounters where pairs of employees made purchases together in 2015–2016. The healthfulness of food items was defined by ‘traffic light’ labels. Cross-sectional simultaneously autoregressive models revealed that proportions of both healthy and unhealthy items purchased were positively associated between connected employees. Longitudinal generalized estimating equation models also found positive associations between an employee’s current food purchase and the most recent previous food purchase a coworker made together with the employee. These data indicate that workplace interventions to promote healthy eating and reduce obesity should test peer-based strategies.

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Fig. 1: Properties of the predictive model for identifying social ties using cafeteria transaction and human resources data.
Fig. 2: Yearly associations between employee and coworker purchases.
Fig. 3: Prospective associations between employee’ current and coworker’s previous purchases.

Data availability

Although the data are deidentified, combined demographic data could potentially identify individuals or small groups. As a result, interested parties may access the data by applying to the corresponding author and entering into an appropriate data use agreement.

Code availability

The R code used to estimate the SAR, GEE and instrumental variables models is illustrated in Supplementary Figs. 1012. Full code is available on request to the corresponding author.


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This work was supported in part by a National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) R21-DK109548 grant to D.E.L. and a National Heart Lung and Blood Institute (NHLBI) R01-HL125486 grant to A.N.T. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the paper.

Author information




D.E.L., M.C.P., A.J.O. and A.N.T. designed the research. D.E.L., M.C.P. and A.Y. performed the research. D.E.L., M.C.P. and B.P. analysed data. D.E.L., M.C.P., A.J.O. and A.N.T. wrote the paper.

Corresponding author

Correspondence to Douglas E. Levy.

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Competing interests

The cafeterias providing data for this project are owned by the MGH, which employs D.E.L., B.P. and A.N.T. The remaining authors declare no competing interests.

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Peer review information Nature Human Behaviour thanks Christopher Gardner and George Wood for their contribution to the peer review of this work. Peer reviewer reports are available.

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Supplementary Methods, Supplementary Figs. 1–12 and Supplementary Tables 1–15.

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Levy, D.E., Pachucki, M.C., O’Malley, A.J. et al. Social connections and the healthfulness of food choices in an employee population. Nat Hum Behav (2021).

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