International organisations including the World Health Organisation (WHO) and the United Nations Fund for Children (UNICEF) have been on the frontline of advocating for breastfeeding for children, especially exclusive breastfeeding for the first six months of the infant and then continued complementary feeding up to two years (1, 2). To ensure a smooth transition to successful breastfeeding, it is recommended that breastfeeding is initiated within one hour of birth (3). This promotes emotional bonding between the mother and the infant, and has a positive impact on breastfeeding duration. It has been observed that breastfeeding durations are longer in low- and middle-income countries compared to high-income countries (2).

The potential of breastfeeding in protecting women against overweight and obesity has equally been recognized but much less explored. Overweight and obesity have become a public health concern in countries worldwide, with recent rapid increases in prevalence among women of reproductive ages in low- and middle-income countries (4). Globally, about 40 percent of women are categorized as overweight and approximately 15 percent are obese (5). Overweight and obesity have become much more common in sub-Saharan Africa (6). For example, the Ghana Demographic and Health Survey (GDHS) reported an increasing trend in overweight and obesity from 25 percent in 2003, and 40 percent in 2014 to half (50%) of females in their reproductive ages (15–49 years) in 2022 (7–9). It is predicted that one in five women will be obese in 2030 (10). These observed increases in body mass index (BMI) of women have been linked to urbanization and unhealthy dietary habits (11). Nonetheless, epidemiological studies espouse the importance of breastfeeding in mitigating overweight and obesity in women (12).

Breastfeeding duration has been shown to minimize the accumulation of excessive fat in lactating mothers (13). Epidemiological data indicate that although a woman's body accumulates more fat during pregnancy, the increased metabolism needed to sustain breastfeeding helps to reduce the amount of fat stored during pregnancy (14–16). Less reduction in excess weight during postpartum periods contributes to extra fat accumulation in subsequent pregnancies leading to obesity (17). Yet, mothers who maintain continuous and longer breastfeeding durations have better chances of burning much of the fat accumulated during the pregnancy and postpartum period. Findings from studies show that the energy required by breastfeeding mothers to effectively produce breast milk is about 2.8 megajoules (670 kcal) per day, and out of this, approximately 2.1 megajoules (500 kcal) is obtained from foods consumed and the rest is obtained from fat stored during pregnancy (18). This level of energy expelled by breastfeeding mothers, therefore, suggests the practice of breastfeeding has an effect in reducing pregnancy related body fat accumulation.

The discourse on the association between breastfeeding duration and weight of mothers remains inconclusive. Although some studies point to a positive association between these parameters, almost all the available evidence emanate from more developed countries (19). For instance, Cieśla et al. (20) established an association between breastfeeding and an increase in body mass index in premenopausal women. On a similar tangent, Bobrow et al. (21) found that women who had ever breastfed during their reproductive period had significantly lower odds of being obese or overweight compared to those who never breastfed. Other recent studies (19, 22–24) have similarly established positive associations between breastfeeding duration and obesity among women. Conversely, some studies have demonstrated that (exclusive) breastfeeding was not associated with postpartum maternal weight or body fat (25–28). To the best of our knowledge and searches, there is the absence of empirical studies in Ghana lending evidence to the discourse on breastfeeding effects on women's body mass index. This study, therefore, contributes to the ensuing discourse by examining the effect of breastfeeding duration on overweight and obesity among women in Ghana, based on pooled data from five (5) nationally representative surveys.

Essentially, aggressive promotion of breastfeeding aside from influencing maternal body weights, has the potential to help achieve the Sustainable Development Goals (SDG); importantly, goals 2 (zero hunger) 3 (good health and wellbeing) and 12 (responsible consumption). Hence, this study examined the independent association of breastfeeding duration with overweight and obesity among women of reproductive age (15–49) in Ghana using multiple rounds (1993–2014) of nationally representative GDHS data. Among the pooled sample of 8,516 women who had their last birth in the five-year period preceding each of the surveys, their mean breastfeeding duration was 14.6 (±8.2). Over one-in-five (23%) of these women were either overweight or obese (16% overweight vs. 7% obese). After adjusting for other factors, the analysis revealed a significant inverse association between breastfeeding duration and obesity, with women who breastfed their last child for 13–18 months and longer than 18 months having reduced odds of being obese by 54% and 59%, respectively, compared with those who did not breastfeed their children at all.

The protective effect of longer duration of breastfeeding on obesity among women as demonstrated in this study is congruent with similar studies conducted elsewhere (20, 22, 34–36). A plausible interpretation is that breastfeeding facilitates the loss of weight gained by women through the gestational process and helps restore women's body to its pre-gestational state. Indeed, Yamamoto et al. (34) showed that full breastfeeding produced significantly more postpartum weight loss than mixed feeding or artificial feeding, while Jarlenski et al. (35) indicated that breastfeeding for at least 3 months resulted in 3.2 pounds greater weight loss for women even at 12 months postpartum.

The other covariates found to be associated with overweight and obesity largely corroborate the existing literature on the subject (37, 38). These factors similarly predict both overweight and obesity, with generally stronger effects on being obese than being overweight. Findings in this study suggest that the likelihood of being overweight or obese significantly increased with age. This pattern generally concurs with the literature (39, 40), and could be linked with the reduced metabolism associated with aging. Given that the study sample consists of women of reproductive age, this finding could partly be linked with gestational and postpartum weight gain and retention over their reproductive life course (41, 42). Indeed, this was further reflected in the results showing that women had higher probability of overweight and obesity with increasing parity.

Similarly, positive effects were seen with respect to the association of socioeconomic factors (educational level and wealth quintile) with overweight and obesity in this study, as have been widely reported in the literature (43–46). Unlike in high income countries, higher education and wealth is linked with sedentary lifestyle patterns, access to high caloric diets and reduced physical activity in low- and middle-income countries where the consumption of such diets are construed as luxuries and status symbols (47–49). Married women had significantly higher odds of both being overweight and obese than women in other categories of marital status. Although this observation is in consonance with prior studies (50–53), the plausible explanations to why married women have the tendency to be overweight or obese point towards either the selection or social causation hypotheses. The traditional social valorization of large-bodied women could result in the selection of overweight or obese women into marriage, whereas married associated improved socio-economic status and changes in social obligation, roles and expectations (childbearing and related kin support) could predispose married women to overweight and obesity.

The findings on locality of residence and occupation showing lower odds of overweight and obesity among women residing in rural areas and those engaged in agricultural occupations seem to reinforce each other. Rural folk tend to engage in agricultural activities using physically exerting and labour intensive traditional methods of production, with a sequel protective affect against overweight or obesity compared with other occupations which are typically based in urban settings (46, 54, 55). Providing further support for this is the fact that the results (Table 2) indicate a higher tendency for women involved in agriculture (36%) to breastfeed their children longer the 18 months compared with their counterparts in other occupations. The positive effect of modern contraceptive use on overweight or obesity among women was demonstrated in this study as in others (56). Nonetheless, the strong positive effect of non-hormonal contraceptive use on both overweight and obesity seemed a bit counterintuitive, especially given that they typically do not contain hormones linked with adiposity. Plausibly, women on non-hormonal contraception began with hormonal options with residual weight-gaining effects despite switching to non-hormonal types.

This study's most significant strength rests on the use of multiple rounds of internationally recognized nationally representative survey data, which was collected using robust protocols and methodological design. In addition, the large number of pooled respondents for the purposes of testing the association between breastfeeding duration provides statistical power to the estimations with minimal margin of error. Despite these strengths, the cross-sectional design based on which the data was collected presents limitations with respect to establishing temporality between breastfeeding duration and the subsequent development or otherwise of overweight and obesity. Another limitation of the data is that other important determinants of overweight and obesity such as dietary intake and physical activity patterns of the women could not be accounted for due to the absence of such information in the datasets. On the balance of these strengths and limitations, the study offers some relevant and generalizable insights on the nature of the association of breastfeeding duration with overweight and obesity among reproductive women in Ghana and perhaps beyond.

The current study underscores the potential of longer breastfeeding duration in promoting optimal health and wellbeing of women by lowering their odds of developing obesity. Specifically, this study demonstrates that breastfeeding a child for a minimum of 12 months offers protection against obesity for mothers by at least 54%. Further, the study reinforces the multiple determinants of overweight and obesity among women in their reproductive age. These findings have implications for policy decision-making, including the promotion of prolonged breastfeeding among mothers as a pathway to reducing the burden of noncommunicable diseases associated with obesity among adults, while at the same time preventing childhood nutritional deficiencies and diarrheal infections. Having illuminated some of the at-risk population subgroups (age, educational, wealth status, marital status, parity etc), policy and intervention options could be tailored with such groups in mind. In particular, healthcare providers could tailor breastfeeding duration and obesity related educational messages to these subgroups of women during routine pre- and post-natal care clinic sessions.