Understanding breastfeeding behaviours in women with a BMI ≥30kg/m2

Student thesis: Phd


Background. Breastfeeding has many health benefits for mothers and their infants. In particular, breastfeeding can reduce the risk of obesity and obesity-related diseases. As women with a BMI ≥30kg/m2 and their infants are at an increased risk of these conditions, breastfeeding can offer substantial benefits to this population’s health and well-being. Reports of breastfeeding behaviours show a consistent, global trend of lower rates in women with a BMI ≥30kg/m2 when compared to their healthy-weight counterparts (BMI 18-25kg/m2). Few interventions have been designed to support women with a BMI ≥30kg/m2 to plan or begin and continue breastfeeding, and the majority have been unsuccessful; this may be because psychological factors have yet to be considered and addressed. Therefore, this programme of research aimed to utilise evidence and theory to design and assess the acceptability of a psychological intervention to increase breastfeeding initiation and duration in women with a BMI ≥30kg/m2 who intended to breastfeed. A Patient and Public Involvement (PPI) group of women with a BMI ≥30kg/m2 was established and consulted at all stages. Methods. Four studies were conducted. The first two studies performed separate systematic searches to identify relevant quantitative and qualitative studies which had investigated the influence of psychological factors on breastfeeding behaviours in women with a BMI ≥30kg/m2. A narrative analysis (quantitative studies) and meta-ethnography (qualitative studies) was conducted. A third study used deductive thematic analysis to further investigate the influence of psychological factors on breastfeeding in women with a BMI ≥30kg/m2 in previously collected qualitative interview data. Qualitative interviews were conducted to assess its acceptability in a fourth study. Findings. The first study found 16 psychological factors had been investigated, and that five were associated with breastfeeding. The second found that women with a BMI ≥30kg/m2 experience common breastfeeding difficulties to a greater degree because of their weight. Both reviews highlighted psychological factors which had potential for intervention development, but firm conclusions could not be drawn due to the relative paucity of research in this area. The third study found that all psychological factors were part of breastfeeding experiences in women with a BMI ≥30kg/m2. The findings of all three studies were presented to a stakeholder meeting of health professionals and PPI group members, consensus was gained on the intervention content, format and delivery. Both psychological theory and behaviour change techniques were applied to create ‘The Breastfeeding Workbook’. The fourth study findings suggest the intervention was acceptable to women with a BMI ≥30kg/m2 and showed promise for increasing initiation and duration. Conclusions. The key message from this research is that psychological factors have an important influence on breastfeeding behaviours in women with a BMI ≥30kg/m2, and can be targeted acceptably in an intervention to support initiation and duration. Increasing psychological factors in this way and incorporating the recommendations into current care should improve breastfeeding behaviours in women with a BMI ≥30kg/m2, and ultimately the health of these women and their infants.
Date of Award31 Dec 2020
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorSarah Peters (Supervisor), Tina Lavender (Supervisor), Debbie Smith (Supervisor) & Sinead Currie (Supervisor)


  • Obesity
  • Qualitative
  • Breastfeeding
  • Health psychology
  • BMI

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