The Link Between Couples and Weight

A growing body of research has found a connection between couples and weight.

Many factors, including a shared living environment, play a role in determining body weight. Research shows that people who live together, particularly spouses, tend to have similar BMIs, and if that shared environment is conducive to weight gain, risk of obesity increases.1, 2 For example, in a study that followed newly married spouses for two years, researchers found that the couples had similar BMIs and that marriage was associated with weight gain.3

The reasons why living together may predispose couples to excess weight seem to be twofold. First, marriage generally increases eating opportunities because married people tend to eat together, and they may eat more when dining together than if eating alone. Secondly, the newly married person may have less motivation to stay thin. 3 In a single world, both men and women want to maximize their attractiveness to the opposite sex and that often includes having a healthy body weight. With marriage, the comfort of being in a stable relationship can lead to a reduced commitment to maintaining one's weight.

Losing weight as a couple works
The good news is that couples who join forces to lose weight may be more successful than those who go it alone. An Australian study investigated the effects of a 16-week lifestyle-modification program for new couples that recently moved in together. The researchers found that couples who changed their behaviors as a team had better success than those going it alone. The couples lost weight, improved their diet, exercised more and reduced their cholesterol levels. 4,5 Most importantly, one year after the program ended, the couples had maintained their weight loss and improved their overall health.

A study on African-American adults who partnered with a family member to lose weight observed that participants were most successful when their family member actively participated and likewise succeeded in losing weight. 6 A meta-analysis of 34 studies of adults with type 2 diabetes concluded that the only factor associated with weight loss was inclusion of a partner or relative in the treatment program.7

Similar results have also been found in couples working to reduce their risk of disease and increase their activity. A study on close to 1,500 British couples participating in a lifestyle-intervention program to reduce the risk for heart disease found that those who benefited the most had partners who also benefited the most. Conversely, men and women who benefited little from the program had partners who benefited little. 8

In a study on exercise, married couples participating in a program together had significantly higher attendance and a dramatically lower dropout rate than married individuals who participated alone. 9 In fact, only 6 percent of the married couples dropped out compared with 43 percent of the singles.

Bottom Line
Couples working to lose weight or keep the weight off together encourage each other's progress and help each other through the challenges that come with losing weight, improving the odds of weight-loss success and better health.

This content is reviewed regularly. Last updated November 13, 2012.

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1 Bloch KV, Klein CH, de Souza e Silva NA, Nogueira Ada R, Salis LH. Socioeconomic aspects of spousal concordance for hypertension, obesity, and smoking in a community of Rio de Janeiro, Brazil. Arq Bras Cardiol. 2003; 80: 179-86.

2 Katzmarzyk PT, Perusse L, Rao DC, Bouchard, C. Spousal resemblance and risk of 7-year increases in obesity and central adiposity in the Canadian population. Obes Res. 1999; 7: 545-51.

3 Jeffery RW, Rick AM. Cross-sectional and longitudinal associations between body mass index and marriage-related factors. Obes Res. 2002 Aug; 10: 809-15.

4 Burke V, Giangiulio N, Gillam HF, Beilin LJ, Houghton S, Milligan RA. Health promotion in couples adapting to a shared lifestyle. Health Educ Res. 1999; 14: 269-88.

5 Burke V, Mori TA, Giangiulio N, Gillam HF, Beilin LJ, Houghton S, Cutt HE, Mansour J, Wilson A. An innovative program for changing health behaviours. Asia Pac J Clin Nutr. 2002; 11: S586-97.

6 Kumanyika SK, Wadden TA, Shults J, et al. Trial of family and friend support for weight loss in African American adults. Arch Intern Med. 2009 Oct 26;169(19):1795-804.

7 Huisman SD, De Gucht V, Dusseldorp E, Maes S. The effect of weight reduction interventions for persons with type 2 diabetes: a meta-analysis from a self-regulation perspective.. Diabetes Educ. 2009 Sep-Oct;35(5):818-35. Epub 2009 Aug 17.

8 Pyke SD, Wood DA, Kinmonth AL, Thompson SG. Change in coronary risk and coronary risk factor levels in couples following lifestyle intervention. The British Family Heart Study. Arch Fam Med. 1997; 6: 354-60.

9 Wallace JP, Raglin JS, Jastremski CA. Twelve month adherence of adults who joined a fitness program with a spouse vs. without a spouse. J Sports Med Phys Fitness. 1995 Sep;35(3):206-13.