Lifestyle and exercise

Weight loss could affect the way couples interact

“How losing weight can be bad for your relationship, with partners sabotaging diets and rejecting sex,” reports the Mail Online. Though the study it reports on also found weight loss brought many couples closer together.

The study researched an often overlooked issue. That is the impact weight loss may have on a relationship; especially if one partner loses weight while the other remains overweight or obese.

This US study used online questionnaires to investigate behaviours and communication among 21 couples where one person in the couple had recently lost 14 kilograms or more.

The researchers found weight loss could have both positive and negative effects on a relationship, centred around two main themes.

The first theme was termed “heightened communication about weight management”. On the positive side some participants reported that their partner losing weight inspired them to do the same. On the negative side some participants reported resentment about being nagged to lose weight. 

The second theme was termed "changes in intimacy”. While most couples reported becoming closer, some participants reported feeling insecure that their partner had lost weight.

Although this study provides some interesting insights, we cannot assume that its findings will apply to everyone.

It does, however, highlight the fact that weight loss can sometimes have a significant effect on a relationship, be it good or bad. It is something you may wish to discuss with your partner if you are planning to lose weight.

And maybe you could try to lose weight together?

Where did the story come from?

The study was carried out by researchers from North Carolina State University and the University of Texas at Austin in the US. Sources of funding were not reported. The study was published in the peer-reviewed journal Health Communication.

The Mail Online’s reporting of the study mainly focused on the negative findings – which is unsurprising, bad news sells more than good news. Its headline “How losing weight can be bad for your relationship, with partners sabotaging diets and rejecting sex” is not representative of the main finding of the study. Many couples reported that weight loss had a positive effect on their relationship.

Its actual reporting of the study is more representative, though it does not include the researchers’ conclusions that the study findings are not generalisable.

What kind of research was this?

This was a qualitative study looking at how weight loss can affect communication and behaviour in romantic relationships. Specifically the researchers were interested in examining perceptions of how weight loss had an effect on communication and behaviour between a couple, where one person had lost weight and the other had not.

Qualitative studies can provide useful insights at an individual level but these insights should never be assumed to be some sort of universal truth. For example, a similar study involving Indigenous Australian people could come up with entirely different responses.

What did the research involve?

The study included 42 adults (21 ‘romantic’ couples) based across the US, in which one partner had lost 30 pounds (approximately 14 kilograms) or more in the two years prior to the study. There were no restrictions placed on how the person had lost weight, for example this could have been through weight loss programs, surgery, dieting and /or exercise, however women who had lost the weight following pregnancy were not included.

The researchers say the couples did not have to be married or heterosexual (in a male/female relationship), but had to have been together before the weight loss occurred and be living together at the time of the study.

The couples were recruited through various sources, including word of mouth, postings on weight-loss blogs and weight-loss surgery support groups.

The participants were asked to complete separate online questionnaires – one questionnaire for those that had lost weight and a separate questionnaire for those that had not lost weight. Online questionnaires were reported to be chosen due to being less threatening than face-to-face interviews. They were asked not to consult their partner when completing the questionnaire.

The questionnaire included a series of 30 open ended questions. The exact questions are not provided by the researchers, but they say participants were asked:

  • about their interaction with one another about weight management before and after one of the partner’s weight loss
  • to describe the consequences of weight loss on their own health or their partner’s health, and the extent to which this surprised them
  • to share any additional information about the effects of the weight loss
  • about the person’s sex, age, height, weight and length of relationship 

Following completion of the questionnaires, each participant received a US$10 gift card to use at a food chain or one of two national businesses (actual businesses not reported).

The two researchers then used qualitative methods to analyse the results and grouped answers into themes where topics or phrases were repeated.

What were the basic results?

The age of the participants ranged from 20 to 61 years, the length of relationship ranged from 2 to 33 years, and the majority of the participants were white (88%). The body mass index (BMI) for non-weight loss participants ranged from 17.7 (considered underweight) to 34.6 (considered obese). The BMI for the participants who lost weight (after weight loss) ranged from 19.5 (considered normal weight) to 48.0.

The researchers say the study showed weight loss can result in both beneficial and negative interactions. They report that two main themes emerged from the analysis, which are described briefly below.

Theme 1: ‘Heightened communication about weight management’

Many of the partners of the person who had lost the weight perceived communication about weight management to have been limited or ineffective prior to the weight loss. After losing weight, many of the participants perceived it was common for the person who lost the weight to talk more about their weight management and to encourage and inspire family members to lead a healthy lifestyle.

The researchers also found that some participants who had lost weight went ‘from pudgy to pestering’ and nagged their partners to follow their lead and lose weight.

Theme 2: ‘Changes in intimacy’

Following weight loss, participants commonly perceived their intimacy levels to change, which was reflected in their communication. The researchers say most couples said their interaction had become more positive and that they had become physically and emotionally closer, such as a strengthened sexual relationship.

However, they said some participants reported negative behaviours such as criticism and insecure comments from partners who had not lost weight, such as participants who had not lost weight feeling negative about themselves for not also losing weight. Another negative finding the researchers reported was that two participants who had lost weight felt more assertive which prompted them to exhibit ‘potentially relationship-disrupting behaviours’.

How did the researchers interpret the results?

The researchers concluded that while losing weight resulted in positive interaction for many partners (such as engaging in a shared healthy lifestyle), shedding weight also led to some negative consequences (for example non-weight-loss partner criticism). They say the extent to which partners embraced new weight management rules and patterns influenced post-weight-loss communication and behaviour.

The Mail Online quotes Dr Romo, one of the researchers, as saying: “This study found that one partner’s lifestyle change influenced the dynamic of couples’ interaction in a variety of positive or negative ways, tipping the scale of romantic relationships in a potentially upward or downward direction.”


The interesting nature of this study provides some insights into the effects of weight loss on relationships, though limited conclusions can be drawn about the strength of any effect on behaviours and communication from this qualitative research.

It is common for qualitative research to include smaller numbers, this study only included 21 couples, all based in the US, so asking the same questions to a different group of people from different ethnicities or countries may result in different answers.

Furthermore, the researchers say that as online questionnaires were used, this may have excluded groups without internet access, such as those with lower incomes or elderly people from participating in the study. As the study only included couples where one person had lost weight, the findings do not apply to couples in which both people have lost weight or are trying to maintain weight loss. 

The researchers do note that although their findings provide an understanding of how and why weight loss can affect couples’ post weight-loss interactions, the findings are not generalisable, possibly due to the reasons pointed out above, although they do not explain their exact reasoning.

To draw firmer conclusions about the effects on behaviour after one person in a couple loses a substantial amount of weight, larger studies with more diverse populations are required.   

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