Historically, obesity was associated with affluence and an extravagant lifestyle; however, its prevalence is increasing worldwide among the poor and the rich (World Health Organization [WHO], 2015). The benefits of weight loss in obese individuals to avoid comorbid conditions are well documented, and WHO has provided guidelines for combating obesity (e.g. Interventions on diet and physical activity: what works). Similarly, the UK Department of Health (DoH) has identified priority areas for targeting obesity (DoH, 2015), and NICE has introduced quality standards to meet these objectives (NICE, 2014). Although there is a link between obesity and type 2 diabetes, not every person who is obese or overweight will develop diabetes (Rajeswaran, 2014); nevertheless, people who are obese or overweight and have diabetes are more prone to have complications compared to people who are not obese. Diabetes can greatly affect an individual’s personal, social and family life (WHO, 2015); therefore, obese people who have diabetes may benefit from losing weight (Rajeswaran, 2014).
The interventions for weight management include drug therapy, bariatric surgery and behavioural interventions, such as diet and physical activity. Studies have found that exercise for people with type 2 diabetes is beneficial (Norris et al, 2009; Thomas et al, 2009). However, even though some patients acknowledge the benefits of keeping a healthy weight (Searle and Ready, 1991; Van Rooijen, 2002; Ali et al, 2010), compliance with weight control interventions can sometimes be challenging. NICE (2014) and the DoH both recommend adults take part in a minimum of 75 minutes of vigorous activity or 150 minutes of moderate activity per week. Jelleyman and Yates (2014) suggest that as low as 5% of people achieve this recommendation.
The prevention of obesity in the UK is currently addressed in several policy documents by the DoH (2007) and NICE (2014; 2015), and by initiatives such as the Healthy Schools programme and food labelling regulations. Although NICE (2014) provides a clear guideline on weight management, current projection indicates an increase in the prevalence of obesity, which could lead to both economic and human consequences. To achieve the goal of international and national strategies for obesity, which seek to maintain healthy weight, the potential barriers to weight control need to be addressed. Diabetes, in all its forms, costs the NHS £10 billion each year to treat; 80% of which is due to treating the complications alone (Diabetes UK, 2014). People with obesity and type 2 diabetes are at high risk of complications due to hyperglycaemia; therefore, it is imperative to identify the factors preventing this population from engaging in physical activity. This systematic review will aim to identify the barriers affecting people with obesity and type 2 diabetes to achieve and maintain weight loss.
A search of health-related databases CINAHL, Medline, EMBASE, EBSCOhost, PubMed, PsycINFO, Ovid and the Cochrane database of systematic reviews was conducted from inception to June 2015. Suitable articles were also selected manually from the references of key articles.
The search terms used were “obesity”, “type 2 diabetes”, “barriers”, “weight control” “weight reduction”, “overweight”, “altered blood glucose level”, “physical activity”, “exercise”, “diet/nutrition”, “lifestyle”, “social behaviour”, “self-esteem” and “psychological impact of diabetes”. Synonyms, Boolean operator and truncation symbols were used to focus and expand the search to retrieve a wide range of relevant studies that were deemed appropriate to the topic under review.
Articles were included if they were written in English, were primary research studies or systematic reviews and peer-reviewed. Worldwide articles were included to give a broad perspective on the topic under investigation. The exclusion criterion for the systematic review were non-research studies, such as reports and literature review, unpublished studies and studies relating to weight control among people with other medical conditions.
Selection of studies and data extraction
The abstracts of the research studies that met the criteria for this systematic review were skimmed online using the PQRS approach (preview, question, read and summarise) described by Cronin et al (2008). Articles that were deemed relevant were subjected to a self-developed form based on a critical appraisal skills programme (CASP) checklist to appraise the selected studies (Public Health Resource Unit, 2008), and to standardise and extract information from the studies. The reviewer repeatedly read all the articles, made comparisons between each study and combined the research papers. The final strategy adopted was a narrative synthesis strategy to provide a structured summary of the available evidence relating to the series of studies under review (Pope et al, 2008) to collate common themes.
Methodological characteristics of the study
A systematic search using both electronic and manual searches of bibliographies revealed a vast amount of literature. An initial search of the electronic databases identified over 14500 potential studies and 733 papers were reviewed at the abstract level (Figure 1). Through careful scrutiny, full texts of all relevant articles (n=46) that met the eligibility criteria were retrieved. Twenty-nine articles were discarded at this stage, mainly due to overlapping, focusing on weight control in other medical conditions or in obesity only, and investigating therapeutic approaches to weight control. Four articles were included from manual searches of references, so that 21 articles made the final selection to be included in the systematic review.
In total, there were 3567 participants included in the 21 articles (Table 1). Most participants were individuals with diabetes, a small number (n=29) were primary care practitioners, dietitians and nurses (Ali et al, 2008-2009), and 143 were diabetes educators (Shultz et al, 2001). Nine of the studies were conducted in the USA, three in the UK, three in the United Arab Emirates, two in Finland and one each in Canada, South Africa and Australia. The sample size of the primary research studies varied, ranging from 21 participants (Visram et al, 2008) to 605 participants (Wanko et al, 2004). The 21 articles consisted of 12 quantitative studies, eight qualitative studies and one systematic review of 13 papers on the barriers to exercise among adults with type 2 diabetes or at high risk (Korkiakangas et al, 2009).
The data collection methods used by the studies were questionnaires, interviews and focus group discussions. The studies used various methods of analysis, predominantly content or thematic analysis for the qualitative studies and descriptive statistics for the quantitative studies. All the studies used non-probability sampling as a way to collect information from key respondents (Polit and Beck, 2012).
Barriers to weight control
All the studies explored the barriers to weight management in obese people with or at high risk of type 2 diabetes. Some of the studies also investigated the motivators for change.
Eighteen studies (86%) identified health problems leading to limited physical and mental capabilities as a barrier to achieving and maintaining weight loss. Half of the primary studies (n=10) included in the review showed that lack of time was a barrier. Almost a third (n=6) reported bad weather conditions as a barrier; however, while most studies meant cold weather, the Ali et al (2010) study conducted in United Arab Emirates reported that hot weather conditions prevented outdoor activities, denoting the impact of both extreme weather conditions.
Other barriers to achieving normal weight included laziness (n=3), stress (n=2), fear (n=3), shyness (n=2), safety concerns (n=3), female gender (n=4) and having a domestic helper (n=2). In some instances, exercise was often thought of as not interesting and boring or not comfortable (n=3).
Six of the 21 studies reported a lack of social support, and an almost equal number (n=5) reported a lack of culturally acceptable facilities for exercise as barriers to weight control. It was identified that societal acceptance of being overweight (Van Rooijen, 2002; Ali et al, 2008-2009) can be a barrier to losing weight. Studies carried out by Dutton et al (2005) and Korkiakangas et al (2009) identified lack of adequate facilities for sport as a problem. One of the oldest studies in the review identified high expenses as a barrier (Searle and Ready, 1991). Personal circumstances, such as starting a first job, moving house or getting married (Thomas et al, 2004) hindered participation in weight control activities. Difficulties also arose from work (n=4), lack of interest (n=3), travel and vacation (Vanderwood et al, 2010). There was also a perception that performing other hobbies and activities such as walking and cooking are a form of exercise (n=2).
Three articles highlighted barriers relating specifically to dietary changes (Ali et al, 2008-2009; 2010; Vanderwood et al, 2010). These included low nutritional knowledge, easy access to junk food and difficulty in controlling appetite. Lack of motivation due to uncontrollable weight was also a barrier to healthy eating.
Motivators to attendance
Korkiakangas et al (2009; 2010), Ali et al (2008-2009; 2010), Donahue et al (2006) and Mier et al (2007) highlighted some of the motivators to attending physical activity. These were personal interest to maintain physical fitness, willingness to prevent deterioration, eagerness to promote independence among the elderly, support, encouragement and enjoyment derived from physical exercise.
Discussion of findings
This section presents an amalgamation of the findings of the current systematic review. The reported barriers were categorised into three broad areas: individual-related barriers, socio-cultural barriers and environmental barriers.
Ill-health was a major barrier reported by nearly all the studies. Lack of energy and poor physical and mental health coupled with advance age was identified by several studies. While some participants could be using it as an excuse, this is consistent with pathophysiology of diabetes in term of its aetiology and symptoms (Marie and Whitaker, 2004; Dixon and Salamanson, 2006). Laziness or lack of interest and motivation, which undermine individual effort to engage with healthcare facilities, was also identified as a barrier to weight loss. Other personal circumstances revealed by the review were lack of time, childcare, lack of convenient venue, and cost. Funding arrangements in the studied country could be a contributor for cost being an identified barrier. These findings are consistent with a range of other studies regarding barriers associated with other medical interventions (Temple and Epp, 2009; Lawal, 2014).
The increased prevalence of obesity with the assumption that behavioural risk factors have a role to play has led to the proposition of a “fat tax” as a potential remedy (Meetoo and Fatani, 2014). Arguably, patients have some responsibilities to achieve and maintain their good health, and the state has a legitimate role to influence people to choose healthy lifestyles (Baggott, 2010). Therefore, practitioners need to consider the patient’s motivation, physical and mental health status, ability, interest, cultural values and social preferences in regards to achieving and maintaining weight loss.
Some obese people have low self-esteem which can affect their confidence to participate in lifestyle-changing activities (National Obesity Observatory, 2011). Similar results identified in this systematic review identified shyness as a barrier to engaging in weight loss interventions (Searle and Ready, 1991). The studies also identified lack of social support, access to house help and lack of culturally acceptable facilities as barriers. Some women interviewed as part of the included studies, were not comfortable performing exercise with men (Ali et al, 2010). Some cultures have a more tolerant attitude towards obesity (Van Rooijen, 2002; Ali et al, 2008-2009), which affects perceptions and normalises obesity and was, therefore, a barrier to engaging with weight loss strategies.
The current systematic review found that external factors such as lack of adequate facilities, accessibility, weather condition and security concerns were a barrier to achieving and maintaining weight loss (Thomas et al, 2004; Dutton et al, 2005). Improving access to services requires a coordinated effort between healthcare practitioners and the activities providers. Srinivasan (2014) emphasised the importance of a cohesive multidisciplinary approach to care for obese people with diabetes. However, multidisciplinary care for obese people with diabetes still seems inadequate in the UK and sometimes individuals will need to make two separate visits in some localities (Srinivasan, 2014).
Predictors of engagement
The studies cite personal circumstances and individual perceptions and preferences as the core barrier to participation in weight control measures. Therefore, personal motivation is a key predictor of engagement (Donahue et al, 2006; Mier et al, 2007; Korkiakangas et al, 2010). Anderson and Funnell (2009) argue that internal motivation is more beneficial in ensuring compliance to health interventions in comparison to external motivation. Maintaining weight or preventing weight regain after weight loss can be challenging for the individual (Rajeswaran, 2013) and Adler and Stewart (2009) opined that tension could arise between empowering people to manage their weight and blaming them for their failure to adhere to the weight control measures. This requires understanding and support from practitioners and the public. As a result, highlighting the impact of the individual’s perceptions about their weight as a barrier, understanding their beliefs and intervening appropriately are all important.
Strengths and limitations
The strengths of this systematic review included the inclusion of healthcare professionals in the studied population. Ali et al (2008-2009) and Shultz et al (2001) investigated the perspectives of the practitioners, which demonstrated and highlighted the importance of health professionals’ role in promoting weight management.
The authors of the articles had a wide academic and professional experience, which adds to the credibility of the limited studies available on the phenomenon, and the studies covered a large geographical range including America, Europe, the Middle East and beyond.
A key limitation of this systematic review is the heterogeneity in the study designs for the included articles. Sample sizes and selection techniques varied, as did the baseline characteristics and socio-economic status of the study populations.
Another potential limitation is the loss of information due to interview methodology. Some studies were conducted in other languages and translated into English (Van Rooijen, 2002; Lawton et al, 2006; Ali et al, 2010), and others did not audio record the interviews (Ali et al, 2008-2009). Thus, the results need to be interpreted within the limit of these methodological constraints.
There were few studies conducted in the UK, so studies from other countries were included. Other countries have different cultural beliefs, health care systems and funding approaches; therefore, considering whether the barriers to achieving and maintaining weight loss are relevant to the UK is difficult (Lawal, 2014).
Implications of the review
The impact of obesity on diabetes and the need to achieve the goals of both international and national strategy for combating obesity justified the rationale for this systematic review. The ability to overcome the potential barriers is important to weight control and the findings have highlighted some of these barriers. While some participants acknowledged the need to keep healthy (Searle and Ready, 1991; Van Rooijen, 2002; Ali et al, 2010), this review has further illuminated the challenges confronting people who are obese in sustaining the effort to maintain weight loss and offers some suggestions on how to address the problems. Weight loss can be promoted through proper coordination of resources, educating patients, effective national policies, and supportive network and healthcare practitioners.
The health consequences of obesity and diabetes require effective management. Regardless of the health concerns and availability of guidelines to tackle obesity, this systematic review of literature revealed that encouraging people who are obese or overweight to be physically active remains a challenge. On the basis of this systematic review, encouraging individuals to change their lifestyle requires promoting autonomy, providing social and culturally acceptable facilities and avoiding blaming or stereotyping. It is important to understand a patient’s perception about their weight, and good communication and effective inter-agency collaboration is essential.