Elsevier

Economics & Human Biology

Volume 6, Issue 3, December 2008, Pages 330-349
Economics & Human Biology

For better or worse: Relationship status and body mass index

https://doi.org/10.1016/j.ehb.2008.07.003Get rights and content

Abstract

Recent increases in the incidence of obesity and declines in marriage have prompted policymakers to implement policies to mitigate these trends. This paper examines the link between these two outcomes. There are four hypotheses (selection, protection, social obligation and marriage market) that might explain the relationship between marital status transitions and changes in Body Mass Index (BMI). The selection hypothesis suggests that those with a lower BMI are more likely to be selected into marriage. The protection hypothesis states that married adults will have better physical health as a result of the increased social support and reduced incidence of risky behavior among married individuals. The social obligation hypothesis states that those in relationships may eat more regular meals and/or richer and denser foods due to social obligations which may arise because of marriage. Finally, the marriage market hypothesis indicates that when adults are no longer in the marriage market they may not maintain a healthy BMI because doing so is costly and they are in a stable union—or on the other hand, adults may enhance their prospects in the marriage market by losing weight. Taking advantage of longitudinal data and complete marriage histories in the National Longitudinal Survey of Youth 1979, we estimate individual fixed effects models to examine associations between the change in log BMI and the incidence of overweight and obesity, and changes in relationship status controlling for the effects of aging and other respondent characteristics. We find no support for the marriage protection hypothesis. Rather we find evidence supporting the social obligation and marriage market hypotheses—BMI increases for both men and women during marriage and in the course of a cohabiting relationship. Separate analyses by race and ethnicity reveal substantial differences in the response of BMI to relationship status across these groups.

Introduction

Marriage has become an increasingly important topic of social science research. It has been associated with positive changes in labor market productivity and compensation. In particular, married men are found to earn more than unmarried men, even controlling for education, age, occupation and industry, and person-specific fixed effects to control for selection into marriage. This marriage-wage premium is a phenomenon observed not only in the U.S. (recent empirical studies using U.S. data include Averett et al., 2006, Light, 2004, Stratton and Leslie, 2002, Chun and Lee, 2001, Hersch and Stratton, 2000) but also in other countries (see Richardson, 2000, Gupta et al., 2005)

There is also a burgeoning literature that links marital status to health outcomes and longevity (see Wilson and Oswald, 2005, Wood et al., 2007 for recent reviews of this literature). Different researchers focus on various measures of health, ranging from self-reported health to mortality rates. In addition there is evidence that after marriage individuals (men in particular) reduce risky behaviors associated with health such as smoking (Duncan et al., 2006). Generally, these studies suggest the existence of a marriage-health premium.

In this paper, we estimate the association between relationship status and one important indicator of health—the Body Mass Index (BMI), and particularly unhealthy levels of the BMI such as overweight and obesity. Recent decades have seen significant changes in the prevalence of obesity and overweight nationally and internationally.1 In the United States the prevalence of obesity for adults 20–74 years of age has increased from 15 percent in the late 1970s to 32.2 percent in 2003–2004 (Flegal et al., 2002, Ogden et al., 2006). From 2000 to 2005 alone, the prevalence of obesity among adults in the U.S. rose 24 percent (Strum, 2007). Obesity is linked to chronic illnesses including diabetes, hypertension, asthma, heart disease, and cancer and is estimated to affect more people than smoking, heavy drinking or poverty (Sturm, 2002, Sturm and Wells, 2001).

In this research we add to the existing literature on marital status and health by explicitly considering cohabitation as a separate relationship status. Most previous work on the health effects of marriage has treated cohabiting individuals as if they were single. The evidence regarding whether cohabitation confers the same benefits of marriage is mixed. There exist a number of studies that establish that the financial and health benefits of relationship status are somewhat unique to marriage (e.g. Waite and Gallagher, 2000). This may be because in marriage, which in the U.S. is a more stable relationship than cohabitation, individuals are more likely to invest by specializing. However, other research suggests that the type of relationship does not matter (Lillard and Panis, 1996).

We use data from the 1979 cohort of the National Longitudinal Survey of Youth (NLSY79), a longer panel data set than used in earlier work, to sort out the association between relationship status and BMI. Although our results do not distinguish the route through which relationship status affects BMI, they provide important evidence about a link between relationship status and obesity. We might expect systematic associations between marriage and BMI for four reasons. Marriage may confer protective effects, individuals may alter their BMI as they move in and out of the marriage market, partnered individuals may engage in social eating behaviors and activities or because individuals who marry are a select group, inherently different from those who do not marry. We expand on these explanations in the next section.

Section snippets

The theoretical link between marriage and health

There are several competing, but not mutually exclusive theories that have been offered to explain the well-documented positive correlation between marriage and various measures of health status and mortality. The marriage selection hypothesis suggests that the healthy are selected into marriage because they make better marriage partners. According to this argument, an observed correlation between marital status and health is not causal—i.e. not a function of marriage per se but rather a

Previous empirical research on the link between marriage and health

A consistent finding in previous cross-sectional studies is that married people enjoy better health and live longer than their unmarried counterparts. Only relatively recently have researchers tried to disentangle the selection and protection effects of marriage by using longitudinal data. A recent review by Wilson and Oswald (2005) provides an excellent summary of this literature and a more comprehensive review than is included here. Interestingly, Wilson and Oswald note, that although

Data and econometric model

To examine the link between relationship status and BMI we use data from the 1979 cohort of the National Longitudinal Survey of Work Experience of Youth (NLSY79). These data are a nationally representative sample, that includes a weighted oversample of Hispanics, African-Americans and low-income whites. The survey respondents, over 12,000 young men and women, were between the ages of 14 and 22 in 1979. The advantage of the NLSY79 data is that respondents were surveyed annually from 1979 to 1994

Results

Given the potentially important role of selection in marriage decisions, we begin our empirical analysis by estimating a model of logged BMI measured in 1981 on whether an individual ever marries using as our sample all individuals who reported having never been married in 1981—the first year of our panel. The first column of Table 2 indicates that women who are single in 1981 and who subsequently marry have a 1981 BMI 6.2 percent lower than those who do not ever marry. This finding is

Marital status and body weight by race and ethnicity

Marriage and cohabitation rates vary considerably by race. Data from the 1995 round of the National Survey of Family Growth, for example, reveal that 47.4 percent of Hispanics were currently married compared to 54.3 percent of whites and 25.2 percent of blacks. Hispanics are slightly more likely to cohabit (8.2 percent) when compared to whites (6.9 percent) and blacks (7.0 percent) (Bramlett and Mosher, 2002). For this reason, we examine the patterns of weight changes and marital status

Conclusions

Our research examines the effect of relationship status on BMI and on important measures of health such as the likelihood of being underweight, overweight and obese. We use data from the National Longitudinal Survey of Youth 1979 cohort to examine the impact of changes in formal (marriage and divorce) and informal (cohabitation) relationships between 1981 and 2004. The panel nature of the data allows us to look at changes over time while differencing out individual time-invariant heterogeneity.

References (41)

  • J. Cawley et al.

    Beyond BMI: the value of more accurate measures of fatness and obesity in social science research

    Journal of Health Economics

    (2008)
  • Christakis et al.

    The spread of obesity in a large social network over 32 years

    New England Journal of Medicine

    (2007)
  • Chun et al.

    Why do married men earn more: productivity or marriage selection?

    Economic Inquiry

    (2001)
  • Conely, D., Glauber, R., 2005. Gender, body mass and economic status. NBER Working Paper...
  • G.J. Duncan et al.

    Cleaning up their act: the effects of marriage and cohabitation on licit and illicit drug use

    Demography

    (2006)
  • K.M. Flegal et al.

    Prevalence and trends in obesity among US adults, 1999–2000

    Journal of the American Medical Association

    (2002)
  • Gupta, N.D., Smith, N., Stratton, L., 2005. Is marriage poisonous? Are relationships taxing? An analysis of the male...
  • D.P. Goldman et al.

    Can Patient Self-Management Help Explain the SES Health Gradient?

    Proceedings of the National Academy of Sciences

    (2002)
  • J. Hersch et al.

    Household specialization and the male marriage wage premium

    Industrial and Labor Relations Review

    (2000)
  • C. Hobson et al.

    Stressful life events: a revision and update of the social readjustment rating scale

    International Journal of Stress Management

    (1998)
  • Cited by (145)

    • Impact of changes in relationship status on smoking behavior and body weight

      2022, Economics and Human Biology
      Citation Excerpt :

      Averett et al. (2008, 2013) and Meltzer et al. (2013) also observe weight gains after transition to marriage using longitudinal data—consistent with the marriage market hypothesis, which states that those individuals gain weight who are no longer on the marriage market and, thus, no longer concerned with attracting a mating partner (e.g., Averett et al., 2013).2 With a similar reasoning, individuals strive to lose weight with increasing risk of divorce or after divorce (Lundborg et al., 2007; Averett et al., 2008).3 Oliveira et al. (2013), however, identify divorced or widowed individuals as having a higher risk of becoming obese than those who remained married, although women have a lower risk of obesity following a change in marital status.

    • Is a ‘culture of plus-size women’ the independent effect of neighborhood disadvantage on female BMI? A cross-sectional study in two Chilean Municipalities

      2021, Social Science and Medicine
      Citation Excerpt :

      Fig. 1 shows a visual representation of the analytical framework proposed by this study to analyze the influence of neighborhood disadvantage on female BMI. Parity and marital status were not included in the schematic framework because the evidence suggests that their effect on female BMI is shaped by SES (Averett et al., 2008; Brooks and Maklakov, 2010; Kim et al., 2007; Sobal et al., 2003), and would be conditioned by women's need to comply with the ‘thin ideal’ (Paquette and Raine, 2004; Robinovich et al., 2018). Thereby, the influence of parity and marital status on BMI at neighborhood level would depend on how the social context affects women's parameters for body size (dis)satisfaction and BMI by SES.

    View all citing articles on Scopus
    View full text