This study examined the association between relationship satisfaction and metabolic health markers (BMI, WC, and HbA1c) in 2237 adults aged 40 years and older from Burkina Faso. The findings showed that relationship satisfaction was positively associated with body weight (BMI and WC), contrary to expectations. However, depressive symptoms fully mediated the association between relationship satisfaction and BMI. No significant association was found between relationship satisfaction and HbA1c. Gender and age did not moderate the association between relationship satisfaction and metabolic outcomes.
Relationship satisfaction and body weight
Relationship satisfaction was positively associated with body weight, and significant associations were found after adjustment for various demographic characteristics. Although our study revealed that people with higher BMI tended to be those who were more satisfied in their relationships, it is important to note that the majority of our participants had a BMI within the “normal” range (
n = 1458, 65.6%). When interpreted from a Western perspective, the positive association found in our study might support the mating market theory, which suggests that weight maintenance is motivated to attract a mate. Thus, according to this theory, individuals in less satisfying marriages may be less likely to gain weight to improve their appearance to be more appealing to potential new partners. Given a very slim ideal body image this suggests that satisfying romantic relationships can undermine weight change concerns [
27]. However, caution must be taken when interpreting these results. Firstly, the participants in the previous study were younger and at a different stage of life. Furthermore, the cultural context in Burkina Faso differs significantly, and a Burkinabe spouse may be less likely to seek a divorce. Therefore, the mating market theory may not be applicable in the Burkinabe context.
In contrast to previous studies conducted on Western samples [
7,
8,
28,
29], which consistently reported a negative association between relationship satisfaction and body weight, the present study found different findings. However, the association between relationship satisfaction and BMI in this study may not necessarily indicate an unhealthy body weight. A review study about body image perception among Africans reported that preferences for slightly overweight body sizes are common in many African populations, especially those from rural areas [
30]. In line with these findings, a study among adolescent girls from the Nouna HDSS found that most of their respondents desired a larger body [
31]. Therefore, a higher body weight might represent a beauty or status ideal in the population observed in this study and thus reciprocally improve both partners’ relationship satisfaction. Moreover, within a society where hunger, food insecurity, and limited food availability especially high-calorie and energy-dense foods are common [
32], there might be a perception that a higher BMI or larger body size is desirable, as it might correspond to greater access to food, resource, and overall stability. Other metabolic risk factors such as alcohol consumption, tobacco use, a sedentary lifestyle, and access to leisure activities may also play a role in mediating this association. These factors are more readily accessible to individuals in high-income countries compared to Burkina Faso’s population. Future studies could explore this association in populations at higher metabolic risk, urban residents, and individuals with higher socioeconomic status.
Furthermore, our study found that the association between relationship satisfaction and BMI seems to be entirely mediated by depressive symptoms. This result aligns with previous studies indicating a close link between relationship satisfaction and depressive symptoms [
33,
34]. This also serves as a validation of the results regarding relationship satisfaction and BMI: In this present African sample, we find a linear and negative association of depressive symptoms with BMI, which is in contrast to previous studies from high-income countries [
35]. Being undernourished is a serious health threat to Sub-Saharan residents. However, more refined analyses in our sample do not support curvilinear trend. In comparison to individuals with a normal BMI, depressive symptoms were associated with increased likelihood of being underweight. Conversely, no association was found between depressive symptoms and being overweight or obese (Supplementary Table
1). Interestingly, our study also found no evidence for depressive symptoms mediating the association between relationship satisfaction and waist circumference. This finding contradicts the expected positive association between depressive symptoms and obesity according to prior evidence. Previous studies have consistently reported a positive bidirectional association between depressive symptoms and obesity [
36], as well as a positive association between depressive symptoms and metabolic syndrome [
37]. However, in our prior analysis of the same sample, we did not observe a significant association between depressive symptoms and metabolic syndrome [
38], aligning with findings from other studies conducted among sub-Saharan African populations [
39,
40]. The significant mediation of depressive symptoms in the association between relationship satisfaction and BMI indicates a potential sub-clinical association between depressive symptoms and BMI in this sample of Burkinabe adults.
Additionally, the lack of awareness and knowledge about metabolic risk factors may contribute to the observed association. Engaging in a healthy lifestyle requires individuals to recognize unhealthy behaviors and replace them with healthy ones. However, a study has shown a lack of awareness and knowledge about cardiovascular diseases and their risk factors in sub-Saharan African populations [
41]. This lack of health literacy may lead couples to live metabolically unhealthy lives, despite their desire to prioritize their health. It is important to note as well that health literacy and, to some extent, cultural value play a role in shaping an individual’s knowledge, attitude, and belief regarding their perception of body image. Future studies should explore the role of (metabolic) health literacy as a potential mediating factor, as it could inform public health interventions.
Relationship satisfaction and diabetes
Our study found that there was no significant association between relationship satisfaction and HbA1c levels. The models used in the study had limited explanatory power, as they could only account for 7.9% of the variance in HbA1c values. This suggests that the variables used in the models, including relationship satisfaction, were not well-suited to explaining the differences in HbA1c values. While other studies have reported significant associations between relationship quality and diabetic outcomes, the findings have not always been consistent [
17,
42,
43].
It is possible that a minimum level of exposure to health-deteriorating factors is necessary to establish an association between relationship satisfaction and HbA1c levels. Additionally, theories on the impacts of low relationship quality on health suggests that stress plays a central role in mediating the association between relationship quality and diabetes. It is possible that specific negative aspects of relationship quality, such as conflict or criticism, have a greater impact on participants’ stress levels than overall relationship satisfaction, which was measured in the present study. Previous studies [
17,
40,
41] used a more comprehensive assessment of relationship quality, which may explain why they have found significant associations.
Relationship satisfaction and gender
Our study also found that women reported lower relationship satisfaction than men, but gender did not have a specific effect on the association between relationship satisfaction and metabolic outcomes. The findings regarding gender effects in previous studies have been inconsistent. Some studies have found gender-specific effects, such as a study in the US that found a link between positive marital quality and lower prevalence of diabetes only in men [
17], while another study in New Zealand found that relationship quality was negatively correlated with weight gain only in women [
28]. Additionally, a notable US study found that negative marital quality in men and positive marital quality in women were associated with lower odds of incident diabetes [
42]. However, several studies did not find gender effects in this area [
7,
29,
44]. Women are often suggested to be more emotionally involved in and affected by close or intimate relationships, which potentially leading to a greater influence on their partner’s health and be more sensitive to the quality of their relationship, resulting in more pronounced health effects [
45]. Nevertheless, generalizing gender differences in the association between romantic relationships and metabolic health may not be suitable due to significant cultural variations in gender concepts [
46]. Moreover, since most studies in this field were conducted amongst populations from high-income countries (HIC), data may not be transferable to populations in low-income countries (LIC). Therefore, research conducted among populations living in low-income countries is a valuable addition to the field.
Strengths and limitation
The strengths of the study include its large and randomly selected population-based sample, which enhances the validity of the findings for the Nouna region and possibly other regions in Burkina Faso or sub-Saharan Africa. To our knowledge, the study is also the first to investigate relationship satisfaction in a large sub-Saharan population using the CSI-4 [
21]. Results suggest that per se the CSI-4, as a highly economic and unidimensional measurement instrument, can give a valid impression of relationship satisfaction in non-Western populations and can therefore be used to assess biopsychological associations in different cultures. Based on this, this study is the first to focus on the association between relationship satisfaction and metabolic health in sub-Saharan Africa. The lower rate of marriage dissolution in Burkina Faso compared to the US [
47,
48] provides an opportunity to study the connection between relationship satisfaction and health on a broader scale. In Burkina Faso, women face significant social repercussions after a divorce, making it challenging for them to return to their families and remarry. As a result, couples may stay married for longer, even if the quality of their relationship is poor.
However, our study has several limitations. First, the results may not be generalizable to younger populations as the study only included individuals aged 40 years and older. Second, a cross-sectional study cannot establish causal explanations for the observed associations. Third, the translation of the CSI-4 into French and the local language introduces the risk of translation and interpretation bias, although the instrument showed good internal consistency and distribution in this setting. Future research should optimize study designs by using more refined instruments and multidimensional assessments of relationship quality. Qualitative studies could explore population-specific conceptions of high-quality relationships to inform the choice of appropriate instruments. Additionally, including information on smoking, drinking, and diet may help to explore potential mediating pathways, and thus may lead to better explained variations in the outcomes. Lastly, longitudinal studies are needed to understand the temporal order and trajectories of relationship quality and health status. The majority of the population in our study was within normal BMI range and so it could possibly be difficult to see the association of relationship satisfaction and metabolic health, as this seems indicative that they were not from an area where metabolic health would be impacted by over-nutrition. Moreover, taking into consideration that average BMI was within the normal range, this may provide additional clarification as to why there was no observed mediation effect between depressive symptoms and waist circumference. One possible explanation for this discrepancy could be that BMI and waist circumference represent different aspects of body composition. BMI is a measure of overall body weight relative to height, while waist circumference is a measure of abdominal fat distribution. Therefore, future studies also need to be explored in a population that specifically includes obese Burkinabe people.