Skip to main content
Advertisement
Browse Subject Areas
?

Click through the PLOS taxonomy to find articles in your field.

For more information about PLOS Subject Areas, click here.

  • Loading metrics

Level of dietary adherence and determinants among type 2 diabetes population in Ethiopian: A systemic review with meta-analysis

  • Teshager Weldegiorgis Abate ,

    Roles Conceptualization, Data curation, Formal analysis, Methodology, Software, Writing – original draft, Writing – review & editing

    teshagerhylemarriam@gmail.com

    Affiliation Department of adult health Nursing, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Minale Tareke ,

    Contributed equally to this work with: Minale Tareke, Selam Abate, Ashenafi Genanew

    Roles Conceptualization, Data curation, Writing – review & editing

    Affiliation Department of Psychiatry, School of Medicine, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Selam Abate ,

    Contributed equally to this work with: Minale Tareke, Selam Abate, Ashenafi Genanew

    Roles Conceptualization, Data curation, Writing – original draft

    Affiliation Department of Health Officer, Merawi Primary Hospital, Amhara Health Bureau Dar, Ethiopia

  • Abebu Tegenaw ,

    Roles Data curation, Visualization, Writing – original draft

    ‡ AT, AY, MT, HG and EA also contributed equally to this work.

    Affiliation Department of adult health Nursing, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Minyichil Birhanu,

    Roles Data curation, Formal analysis, Writing – original draft, Writing – review & editing

    Affiliation Department of Pediatric and Child Health Nursing, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Alemshet Yirga ,

    Roles Formal analysis, Methodology, Writing – review & editing

    ‡ AT, AY, MT, HG and EA also contributed equally to this work.

    Affiliation Department of adult health Nursing, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Mulat Tirfie ,

    Roles Conceptualization, Data curation, Writing – original draft, Writing – review & editing

    ‡ AT, AY, MT, HG and EA also contributed equally to this work.

    Affiliation Department of nutrition and dietetics, School of Public Health, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Ashenafi Genanew ,

    Contributed equally to this work with: Minale Tareke, Selam Abate, Ashenafi Genanew

    Roles Data curation, Formal analysis, Investigation, Methodology, Writing – original draft, Writing – review & editing

    Affiliation Department of Pharmacy, School of Health Sciences, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Haileyesus Gedamu ,

    Roles Conceptualization, Data curation, Visualization, Writing – original draft, Writing – review & editing

    ‡ AT, AY, MT, HG and EA also contributed equally to this work.

    Affiliation Department of adult health Nursing, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

  • Emiru Ayalew

    Roles Conceptualization, Data curation, Visualization, Writing – original draft, Writing – review & editing

    ‡ AT, AY, MT, HG and EA also contributed equally to this work.

    Affiliation Department of adult health Nursing, School of Health Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia

Abstract

Background

The beneficial effect of the dietary practice is significant reduction in the risk of developing diabetes related complication. Dietary practice among type 2 diabetes is not well-implemented in Ethiopia. Up to now, in the nation, several primary observational studies have been done on dietary adherence level and its determinants among type 2 diabetes. However, a comprehensive review that would have a lot of strong evidence for designing intervention is lacking. So, this review with a meta-analysis was conducted to bridge this gap.

Methods

A systematic review of an observational study is conducted following the PRISMA checklist. Three reviewers have been searched and extracted from the World Health Organization- Hinari portal (SCOPUS, African Index Medicus, and African Journals Online databases), PubMed, Google Scholar and EMBASE. Articles’ quality was assessed using the Newcastle-Ottawa Scale by two independent reviewers, and only studies with low and moderate risk were included in the final analysis. The review presented the pooled proportion dietary adherence among type2 diabetes and the odds ratios of risk factors favor to dietary adherence after checking for heterogeneity and publication bias. The review has been registered in PROSPERO with protocol number CRD42020149475.

Results

We included 19 primary studies (with 6, 308 participants) in this meta-analysis. The pooled proportion of dietary adherence in the type 2 diabetes population was 41.05% (95% CI: 34.86–47.24, I2 = 93.1%). Educational level (Pooled Odds Ratio (POR): 3.29; 95%CI: 1.41–5.16; I2 = 91.1%), monthly income (POR: 2.50; 95%CI: 1.41–3.52; I2 = 0.0%), and who had dietary knowledge (POR: 2.19; 95%CI: 1.59–2.79; I2 = 0.0%) were statistically significant factors of dietary adherence.

Conclusion

The overall pooled proportion of dietary adherence among type 2 diabetes in Ethiopia was below half. Further works would be needed to improve dietary adherence in the type 2 diabetes population. So, factors that were identified might help to revise the plan set by the country, and further research might be required to health facility fidelity and dietary education according to diabetes recommended dietary guideline.

Background

Half a billion people are living with diabetes worldwide and the number is projected to increase by 25% in 2030 and 51% in 2045 [1], particularly in low-and middle-income countries [2]. Global burden of type 2 diabetes is projected to increase to 7079 individuals per 100,000 by 2030, reflecting a continued rise across all regions of the world [3]. The goals in caring for patients with diabetes mellitus are to eliminate symptoms and to prevent, or at least slow, the development of complications [4].

Diabetes self-management is an essential component of effective self-care practice. Mindful eating offers promise as an effective approach for weight glycemic control in people with type 2 diabetes [5, 6]. Improvement in the elevated blood glucose level can be achieved through diet management [7]. Diets rich in whole grains, fruits, vegetables, legumes, and nuts; moderate in alcohol consumption; and lower in refined grains, red or processed meats, and sugar-sweetened beverages have been shown to reduce the risk of diabetes and improve glycemic control and blood lipids in patients with diabetes [8, 9].

Adherence to a healthy diet is the cornerstone in the prevention and management of diabetes [10, 11]. Medical nutrition therapy is an integral component of diabetes management and of diabetes self-management education [12]. Failure to follow a strict diet plan is leading causes of complications among patients with type 2 diabetes. There are many misconceptions exist concerning nutrition and diabetes, for example (a) do not allocate enough time for baste buds to change; (b) too impatient to see results; (c) having the wrong mindset; (d) lack of support from family, friends and support groups; and (e) lack preparation and planning [9, 13, 14].

The main factors to dietary adherence were both systemic (population changes, poor access to diet, cultural influences, and low-quality healthcare) and personal (poverty and cost, educational status, and perceptions about the disease) in nature [10]. The lack of proper professional dietary assessment, follow-up and advice by the health care providers are the main influence on dietary practice of type 2 diabetes [15].

Dietary adherence in type 2 diabetes has been found to vary from region to region in Ethiopia [1621]. Even though the pooled proportion (50.18%) of good dietary practice among type 2 diabetes is documented in Ethiopia with small sample size [22], the overall dietary adherence and common factors that promote good dietary practice are not documented in the country. Thus, this study aimed to assess the pooled proportion of dietary adherence and associated factors among type 2 diabetes population in Ethiopia.

Materials and methods

Protocol design and registration

A systematic review of an observational study was conducted following the meta-analysis of observational studies in an epidemiology statement. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) [23, 24]) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guideline [25] were used for the development of this study protocol. The protocol of this systematic review and meta-analysis was registered with the International Registration of Systematic Reviews (PROSPERO) with PROSPERO registration number CRD42020149475. The protocol registration aimed to minimize duplication of the same reviews, provide transparency, and reduce reporting bias.

Eligibility criteria

The studies (all published and unpublished) were that used observational epidemiological designs (cross-sectional), intended to assessed dietary adherence and associated factors among people with type 2 diabetes aged 15 and above, and articles that were published in the English language. Studies were conducted in type 1 diabetes and mixed both types, a case series, unclear definition of dietary adherence practice (like unclear measurement of questionnaires in the outcome variables, and did not report specific outcomes for dietary adherence/non-adherence quantitatively) were excluded in the final analysis.

Data sources and searching strategy

A search strategy has been developed using fundamental concepts in the research question: “dietary adherence,” “recommended dietary practice,” “therapy adherence,” “treatment adherence,” “medication intake adherence,” “medication compliance,” “patient compliance,” “diabetes mellitus,” “type 2 diabetes,” “diabetes,” “patients,” “clients,” and “factors,” “determinants,” “influences,” “risk factors,” “predictors” and “Ethiopia”. For each key concept, appropriate free-text words and Medical Subject Heading (MeSH) were used and combined using Boolean operators such as “AND’ and “OR.” This enabled the retrieval of relevant articles that might have used different synonyms for the same word. Notably, to fit the advanced PubMed database, the search was strategy applied (S1 Table).

A pretest of the search strategy by three authors was performed in PubMed, and the actual electronic search was done between 25 February and March 5, 2021. Three reviewers implemented the electronic search in the following electronic databases: PubMed, Embase, GOOGLE SCHOLAR, CINAHL, MEDLINE, and Hinari electronic databases. Hinari is the World Health Organization (WHO) database portal for low and middle income countries and includes Web of Science, SCOPUS, African Index Medicus (AIM), Cumulative Index to Nursing and Allied Health Literature (CINAHL), WHO’s Institutional Repository for Information Sharing (IRIS), and African Journals Online databases. In addition, articles were also searched through a review of the grey literature available on institutional repositories (Addis Ababa, Bahir Dar, and Jimma Universities). Besides, we found other articles by snowballing and retrieving references lists of already identified articles to include studies that were unable to identify by search strategy.

Study selection

All the citation identified by our search strategy, which was potentially eligible for inclusion, was exported to EndNote software version X7, Thomson Reuters, New York, NY, and the duplicate were removed. Title and abstracts of the remaining citation were screened by three independent reviewers (TWA, AT and AY) and ineligible studies were further excluded. The full texts of selected articles were retrieved and read thoroughly to ascertain their suitability before data extraction. The articles that fulfilled the earlier criteria have been used as sources of data for analysis.

Data extraction

The abstract and full-text review and data abstraction were done by two independent reviewers (HG and MB) using a standardized data abstraction form, developed according to the sequence of variables required from primary studies on MS-Excel sheet. The disagreement between the two reviewers was resolved by a third independent reviewer through discussion (SA or EA). Before analysis, a transformation of the adjusted odds ratios and proportion was made.

The New castle Ottawa Scale criteria were selected for quality assessment of selected studies before analysis [26]. Two independent reviewers (TWA and MT) critically appraised each article using the NOS. Discrepancies between reviewers resolved by discussion and by including a third reviewer (EA). We used the average of two independent reviewer’s quality scores used to decide whether the articles included or not. Articles with methodological flaws or incomplete reporting of results in the full-text excluded from the analysis. The data extraction formant included primary author, publication year, region, outcome measuring tool, study design, response rate, sample size, and proportion.

Outcome measurement

The primary outcome of this review was the pooled proportion of dietary adherence among people with type 2 diabetes in Ethiopia. The proportion measured as the number of adult type 2diabetes with dietary adherence in the studies divided by the total number of type 2 diabetes people in a study multiplied by 100. For the analysis of the secondary outcomes (factors), we extracted data on factors that were related to dietary adherence practice in the literature, such as educational level, monthly income, knowledge towards diabetes and diabetes management, and received diabetes self-management education. In examining factors associated with dietary adherence, data used from the primary studies of the Adjusted Odd Ratios (AOR) to find the association between the independent variables and having dietary adherence practice.

Quality assessment

The risk of bias of included studies is assessed using the 10-item rating scale developed by Hoy et al. for prevalence studies [27]. The assessment tool has the following domain of each articles; representative sample size, method of data collection, reliability and validity of study tools, case definition, and prevalence periods of the studies. Researchers categorized each study as having a low risk of bias (“yes” answers to domain questions) or a high risk of bias (“no” answers to domain questions). Each study assigned a score of 1 (Yes) or 0 (No) for each domain, and these domain scores were summed to give an overall study quality score. Scores of 8–10 were considered as having a “low risk of bias”, 6–7 a “moderate risk”, and 0–5 a “high risk” (S3 Table).

Statistical analysis

Testing for heterogeneity.

Heterogeneity between the results of the primary studies was assessed using Cochran’s Q test and quantified with the I2 statistics. A p-value of less than 0.1 was considered to suggest statically significant heterogeneity, considering a category a small number of studies and their heterogeneity in design [28]. Heterogeneity had taken low, moderate, and high categories when the I2 values were below 25%, between 25% and 75%, and above 75%, respectively [29, 30]. Thus, the random effect model was used to pool the proportion of dietary adherence since the studies were found heterogeneous. The random effect model accounts for heterogeneity among study results beyond the variation associated with chance, unlike the fixed-effect model [31].

To investigate the source of heterogeneity, the random-effects meta-regression was conducted by taking primary study characteristics such as region, and study setting (types of hospitals) and outcome measurement tool. The meta-regression analysis was weighted to account for the residual between-study heterogeneity (i.e., heterogeneity not explained by the covariates in the regression) [32]. Subgroup analyses by region, type of study setup (types of hospitals) and outcome measurement tool were carried out because of significant heterogeneity between studies (i.e., I2 = 93.1%, p < 0.05).

Publication bias assessment.

Publication bias was assessed by visual inspection of funnel plots based on the shape of the graph (subjective assessment). The symmetrical graph was interpreted to suggest an absence of publication bias, whereas an asymmetrical one indicates the presence of publication bias. On the other hand, qualitatively (objective evaluation), Egger’s weighted regression tests was used to assess publication bias with a p-value less than 0.1 considered as indicative of a statistically significant publication bias [33].

Sensitivity analysis.

Lastly, a sensitivity analysis was done to estimate whether the pooled effect size was affected by single studies. A leave-one-out sensitivity analysis was performed to confirm whether there were studies that potentially biased the direction of the pooled estimate.

Result

Study selection

The database search and desk review yielded a total of 976 articles. Of these, 968 articles were retrieved from PubMed, Google Scholar, EMBASE, and the World Health Organization’s Hinari portal (which includes the SCOPUS, African Index Medicus, and African Journals Online databases). The remaining 8 observational studies were found from institutional repositories (Addis Ababa, Gondar, and Bahir Dar Universities). After reviewing the titles and abstracts, we excluded 621 articles due to duplication. In screening, we excluded 332 articles because their outcomes were not in line with the desired eligibility criteria. The full-text of the remaining 22 articles has been accessed for eligibility and quality. Additionally, three articles were excluded because their outcomes variables were not clearly stated (34–36). The remaining 19 studies were included in the analysis (Fig 1).

thumbnail
Fig 1. PRISMA statement presentation for a meta-analysis of a pooled proportion of dietary adherence among type 2 DM in Ethiopia, 2012–2020.

https://doi.org/10.1371/journal.pone.0271378.g001

Study characteristics

Overall, a total of 19 observational studies were selected in this systematic review and meta-analysis. This consisted of 6308 participants (aged 15–85 years). The number of participants in each study ranged from 207 to 576. All studies were cross-sectional design to estimate dietary adherence. The most retrieved studies (n = 6) were from Oromia region [18, 3741], followed by Addis Ababa (n = 4) [19, 20, 42, 43], and Amhara region (n = 4) [16, 17, 44, 45], SNNP [46, 47] and Dire Dawa [21, 48] were represented by two studies, whereas Tigray region region was represented by one study [49]. Except for two studies [42, 48], all the studies have been reported in peer-reviewed journals. All of the studies have been reported high response rates (> 92.9%) (S2 Table, Table 1).

thumbnail
Table 1. Descriptive summary of 20 studies included in the meta-analysis of the proportion of dietary adherence among type 2 diabetes population in Ethiopia from 2012–2020.

https://doi.org/10.1371/journal.pone.0271378.t001

Quality appraisal

The quality score of the included study ranged from 6 to 8 with a mean score of 8 .14 (SD = 0.91). Out of 19 studies, 13 (68.42%) studies received a low risk of bias, and four (21.05%) studies received a moderate risk of bias. The authors also find types of bias: eight studies [21, 41, 4345, 47, 48] had a high risk of representation bias and seven studies [21, 3739, 42, 43, 45] had a high risk of case definition bias (S3 Table).

Meta-analysis

Pooled estimates of dietary adherence among type 2 DM in Ethiopia.

The analysis of twenty observational studies was ranked as low and moderate-quality. The pooled proportion of dietary adherence of people with type 2 diabetes was 41.05% (95%CI: 34.86–47.24, I2 = 93.1%). The highest (64%) [18] and the lowest (18.2%) dietary adherence reported in the Oromia region. High heterogeneity was observed among the included studies (Q test P<0.001) and I2 (I2 = 93.1%) (Fig 2). Due to the heterogeneity of included studies, further sub-group analysis was done by using the following study characteristics: regional location (Fig 2), outcome measurement tools and study setting (types of hospital). The random-effect model was applied for reporting the pooled proportion of dietary adherence of the sub-group analysis.

thumbnail
Fig 2. A subgroup analysis of the forest plot showing the pooled proportion of dietary adherence among type 2 DM in Ethiopia, 2012–2020.

https://doi.org/10.1371/journal.pone.0271378.g002

Subgroup analysis.

On subgroup analysis by region, the highest pooled estimation of dietary adherence was found in the SNNP region (Pooled Proportion (PP) = 57.14%; 95% CI: 51.54, 62.75) and the lowest in the Addis Ababa (PP = 33.51%; 95% CI: 20.87, 46.30). The pooled estimation of dietary adherence among type 2 DM in the Dire Dawa city administration was 41.21% (95% CI: 33.76, 48.66), and 44.84% (95% CI: 30.19, 59.50) in Oromia. The pooled estimation of dietary adherence in a referral hospital is 40.40% (95% CI: 33.78, 47.02). The pooled estimation of dietary adherence was high in MMAS-8 scale measurement of dietary adherence level without heterogeneity 48.40% (95% CI: 43.02, 53.78) Table 2).

thumbnail
Table 2. Sub-group analysis of dietary adherence based region, hospital and outcome measurement tool in Ethiopia from 2012 to 2020.

https://doi.org/10.1371/journal.pone.0271378.t002

Publication bias.

Both funnels plots of precision asymmetry and the Egger’s test of the intercept showed that there is no publication bias in the primary studies. Visual examination of the funnel plot showed a symmetric distribution of studies. Additionally, Egger’s test of the intercept was 0.291 (95% CI: -0.085, 0.667) p > 0.05 (0.121), as judged by Egger’s test. This is suggesting that publication bias estimates were not statistically significant (Fig 3).

thumbnail
Fig 3. Meta funnels presentations of the proportion of dietary adherence among type 2 DM in Ethiopia, 2012–2020, whereby SE PIV (standard error of proportion) plotted on the Y-axis and log PIV (logarithm of proportion) on the X-axis.

https://doi.org/10.1371/journal.pone.0271378.g003

Meta-regression and sensitivity analysis.

The sub-group analysis showed that heterogeneity across the studies was widespread. To name the source of heterogeneity, we conducted a meta-regression and sensitivity analysis. During the meta-regression analysis, we conducted using the following study covariance: study years, sample size, and region. However, the results showed that none of these variables were a statistically significant source of heterogeneity (Table 3).

thumbnail
Table 3. Meta-regression output to explore heterogeneity of the pooled proportion of dietary adherence among type 3 diabetes population in Ethiopia from 2012–2020.

https://doi.org/10.1371/journal.pone.0271378.t003

We also performed a sensitivity analysis to find the influence of each study on the overall effect size. No single primary study affected the overall pooled proportion of dietary adherence among people with type 2 diabetes in Ethiopia (Fig 4).

thumbnail
Fig 4. One-leave-out sensitivity analysis for studies conducted on proportion of dietary adherence among people with type 2 DM in Ethiopia, 2012–2020.

https://doi.org/10.1371/journal.pone.0271378.g004

Determinants of dietary adherence

Extracted adjusted odds ratios from the primary studies were educational level, average monthly income, and dietary knowledge and pooled to identify predominantly associated factors for dietary adherence. Accordingly, people who had high level of education (Pooled Odds Ratio (POR): 3.29; 95%CI: 1.41–5.16; I2 = 91.1%) (Fig 5), people who had high level of average monthly income (POR: 2.50; 95%CI: 1.41–3.52; I2 = 0.0%) (Fig 6), and those who had dietary knowledge (POR: 2.19; 95%CI: 1.59–2.79; I2 = 0.0%) (Fig 7) are determinate factors to adhere diet.

thumbnail
Fig 5. A meta-analysis of educational level associated with dietary adherence among type 2 DM population in Ethiopia.

https://doi.org/10.1371/journal.pone.0271378.g005

thumbnail
Fig 6. A meta-analysis of average monthly income associated with dietary adherence among type 2 DM population in Ethiopia.

https://doi.org/10.1371/journal.pone.0271378.g006

thumbnail
Fig 7. A meta-analysis of dietary knowledge associated with dietary adherence among type 2 DM population in Ethiopia.

https://doi.org/10.1371/journal.pone.0271378.g007

Discussion

To the best of our review, this is the first systemic review and meta-analysis study that conducted to show the pooled proportion of dietary adherence and associated factors among type 2 diabetes in Ethiopian. This study identified that less than half people with type 2 diabetes (41.05%) in Ethiopia adhere to dietary practice as recommended or agreed between people with type 2 diabetes and healthcare providers or standard dietary recommendation guideline.

This finding is higher than a study conducted in Brazil (29.2%) [50, 51], Bangladeshi (22%) [52]; but lower than a study conducted in Iran (94.6%) [53]. This is because, in Brazil, consumption of unhealthy diet markers was greatest in diabetes population [54]. Unhealthy eating habits among type 2 diabetes are a significant impact in Bangladeshi [55]. A qualitative study in Iran documented that the food culture largely affects a type 2 DM patient’s adherence to a healthy diet [56]. In Ethiopia, the probable because of (a) low dietary adherence is economic burden of diabetes care is very disastrous among the less privileged populations group [57] (b) no access of healthy dietary habit [7, 58] (c); and not access of recommended diet [59, 60].

Dietary adherence emphasizes the importance of minimizing macro-vascular and micro-vascular complications in people with diabetes [61]. A recommended diet that improve metabolic conditions for type2 DM are Mediterranean diet, a low-carbohydrate/high-protein diet, a vegan diet and a vegetarian diet [61, 62]. That why good dietary adherence improves the effectiveness of pharmacological intervention and promoting healthy lifestyles [63].

People who had high level of education (Pooled Odds Ratio (POR): 3.29; 95%CI: 1.41–5.16; I2 = 91.1%) (Fig 5), people who had high level of average monthly income (POR: 2.50; 95%CI: 1.41–3.52; I2 = 0.0%) (Fig 6), and those who had dietary knowledge (POR: 2.19; 95%CI: 1.59–2.79; I2 = 0.0%) (Fig 7) were determinate factors to adhere diet.

The educational level is a potential determinate to dietary adherence among type 2 DM individuals. Those people with type 2 diabetes who have high levels of education had more likely to dietary adherence behaviors. This finding is in line with a meta-analysis done in China [63], in a large-scale cross-sectional study in Switzerland [64], and Bangladesh [52].

Evidence shows that when people were more educated improves people’s dietary adherence [65], and low educated level linked with inadequate glycemic controls [66]. Scholars identified that people with lower levels of education consume sugar- and fat-rich foods more often and fruit and vegetables less often than adults with a high education level [67]. Therefore, educational level modulates the level of dietary adherence among study participants. Higher education may be related to knowledge and awareness of healthy eating habits. Being higher education levels could lead to having better judgment and decision-making ability for choosing healthy diet and eating behaviors [67].

Participants’ monthly income is associated with dietary adherence. This finding in line with the former studies [68, 69] significantly positive association had observed between higher average monthly income level and better dietary practice. Because participants who had higher income did not worry about food choices, had no difficulty resisting the temptation to eat unhealthy food, and afford healthy food even if being too expensive [68]. Therefore, low-income participants are prone to follow unhealthy diet [69].

The following reason may explain income differences in dietary adherence among type 2 diabetes. (a) High cost of healthy foods, (b) healthy diet may be perceived as being expensive in comparison unhealthy diet group [70, 71], (c) the expenditure of healthy diets increased with increasing income quintiles [72], and (d) socio-economic disparities among individuals [73].

People with type 2 diabetes who have had moderate and high level of dietary knowledge had double pronounced dietary adherence than people with type 2 diabetes who have had a low level of dietary knowledge. This finding agrees with the earlier study [74, 75]. Dietary knowledge enable individuals with type 2 diabetes to make food choices that (a) optimize metabolic self-management, (b) prevent complication, (c) reduced or hold drug intake, and (d) improve quality of life [74].

In addition to this, dietary knowledge is related to self-care behaviors and good dietary adherence [76]. That is why positive aspects of dietary knowledge are healthy eating like increased fruit and vegetable consumption; and a low intake of simple sugars, fat, and salt. Awareness of food, nutritional properties, and recommendations on the size and frequency of consumption must be the primary goals of nutritional education programmers [77]. Dietary knowledge is an integral component of health literacy [78]. Dietary knowledge (high health literacy) of chronic disease patients like type 2 DM is associated with low healthcare costs, optimal self-management, and good health outcomes, especially for type 2 diabetes [79]. Dietary knowledge helps individuals’ impression, process, understand, and communicate diet-related information needed to make informed health decisions [80].

Strength and limitations

This systematic review and meta-analysis have some strength. This study pooled several studies that provide evidence of the pooled proportion of dietary adherence and its determinant among people with type 2 DM. It includes a large sample size which is much more than the sample sizes of each study. We tried to pool the estimated pooled proportion of common determinate of dietary adherence in the nation.

Despite its strengths, the study also has a few limitations. Even though most of the studies had good quality, all primary studies incorporated in this meta-analysis were cross-sectional which is limited in this study. Besides, we tried extensive and diverse search strategies to find all possible available literature, some grey literature, such as conference proceedings, remained difficult to find which turned limit this study. Furthermore, methods applied to measure outcome parameters varied among included studies.

Implication

This study has many implications for clinical practice and future research. Firstly, the health care provider (especially physicians, nurses, dietician, and health educators) can develop effective strategies (follow dietary plan, dietary education and tailoring dietary interventions to a person’s dietary preferences) to improve dietary adherence. Secondly, identifying and understanding factors that favor and restrict dietary practice is the second step in developing evidence-based interventions to promote short and long-term health outcomes and quality of life. Future research should focus on developing and testing a conceptual model (collaborative, client empowerment and enhance capacity link them to dietician and community resource) that can use to enhance dietary adherence in a national context. Ensure that the recommended diets (food) are availability, affordability, and cultural acceptability in the context of Ethiopians.

Conclusions

This meta-analysis revealed that a low proportion of dietary adherence among people with type 2 DM. Educational level, monthly income, and dietary knowledge were significantly associated factors with dietary adherence. Therefore, health care personnel should build the type 2 DM clients’ dietary knowledge based on what they see, hear, feel, and perceive the healthy diet. Increase awareness of the importance of healthy food habits is the first step in altering eating behavior. Ensure more focusing on eating a healthy diet is as preventive and curative measures for diabetes in health education programs as well in medical curricula.

Supporting information

S1 Table. Search strategy applied to PubMed database in the current review.

https://doi.org/10.1371/journal.pone.0271378.s002

(DOCX)

S2 Table. Scoring of the quality of articles by authors using the Newcastle-Ottawa quality assessment tool.

https://doi.org/10.1371/journal.pone.0271378.s003

(DOCX)

S3 Table. Risk of bias assessment tool of eligible articles by using the Hoy 2012 tool.

https://doi.org/10.1371/journal.pone.0271378.s004

(DOCX)

References

  1. 1. Saeedi P, Petersohn I, Salpea P, Malanda B, Karuranga S, Unwin N, et al. Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas.Diabetes Res Clin Pr. 2019;157:107843.
  2. 2. WHO. https://www.who.int/health-topics/diabetes#tab=tab_1.
  3. 3. Khan MAB, Hashim MJ, King JK, Govender RD, Mustafa H, Al Kaabi J. Epidemiology of type 2 diabetes–global burden of disease and forecasted trends. J Epidemiol Glob Health. 2020;10(1):107. pmid:32175717
  4. 4. Khardori R, Griffing G. Type 1 diabetes mellitus treatment & management. Available: Type. 2017;2.
  5. 5. Barclay A, Gilbertson H, Marsh K, Smart CJAfp. Dietary management in diabetes. Aust. Fam. Physican. 2010;39(8):579–83.
  6. 6. Association A. Prevention or Delay of Type 2 Diabetes: Standards of Medical Care in Diabetes—2021. Diabetes care. 2021;44(Supplement 1):S34–S9.
  7. 7. Sami W, Ansari T, Butt NS, Ab Hamid MR. Effect of diet on type 2 diabetes mellitus: A review. Int.J.Health Sci. 2017 Apr;11(2):65.
  8. 8. Ley SH, Hamdy O, Mohan V, Hu FB. Prevention and management of type 2 diabetes: dietary components and nutritional strategies. The Lancet. 2014;383(9933):1999–2007. pmid:24910231
  9. 9. American Diabetes Association. 5. Lifestyle management: standards of medical care in diabetes—2019. Diabetes care. 2019;42(Supplement 1):S46–S60. pmid:30559231
  10. 10. Bekele H, Asefa A, Getachew B, Belete AMJJoDR. Barriers and Strategies to Lifestyle and Dietary Pattern Interventions for Prevention and Management of TYPE-2 Diabetes in Africa, Systematic Review. J.Diabetes Res. 2020;2020.
  11. 11. Alhazmi A, Stojanovski E, McEvoy M, Garg MJJoHN, Dietetics. The association between dietary patterns and type 2 diabetes: a systematic review and meta‐analysis of cohort studies. J Hum Nutr Diet. 2014;27(3):251–60.
  12. 12. Evert AB, Dennison M, Gardner CD, Garvey WT, Lau KHK, MacLeod J, et al. Nutrition therapy for adults with diabetes or prediabetes: a consensus report. Diabetes Care. 2019;42(5):731–54. pmid:31000505
  13. 13. AmericanDiabetesAssociation. Nutrition principles and recommendations in diabetes. Diabetes care. 2004;27(suppl 1):s36–s. pmid:14693924
  14. 14. Landa-Anell MV, Melgarejo-Hernández MA, García-Ulloa AC, Del Razo-Olvera FM, Velázquez-Jurado HR, Hernández-Jiménez S. Barriers to adherence to a nutritional plan and strategies to overcome them in patients with type 2 diabetes mellitus; results after two years of follow-up. Endocrinol. Diabetes Nutr. 2020 Jan 1;67(1):4–12. pmid:31387846
  15. 15. Shamsi N, Shehab Z, AlNahash Z, AlMuhanadi S, Al-Nasir F. Factors influencing dietary practice among type 2 diabetics. Bahrain Med. Bull. 2013;35(3):1–14.
  16. 16. Ayele AA, Emiru YK, Tiruneh SA, Ayele BA, Gebremariam AD, Tegegn HGJCd, et al. Level of adherence to dietary recommendations and barriers among type 2 diabetic patients: a cross-sectional study in an Ethiopian hospital. Clin. Diabetes Endocrinol. 2018;4(1):1–7.
  17. 17. Demilew YM, Alem AT, Emiru AAJBrn. Dietary practice and associated factors among type 2 diabetic patients in Felege Hiwot Regional Referral Hospital, Bahir Dar, Ethiopia. 2018;11(1):1–7.
  18. 18. Zeleke Negera G, Charles Epiphanio DJIjoe. Prevalence and predictors of nonadherence to diet and physical activity recommendations among type 2 diabetes patients in Southwest Ethiopia: a cross-sectional study. Int.J. Endocrinol. 2020;2020.
  19. 19. Worku A, Abebe SM, Wassie MMJS. Dietary practice and associated factors among type 2 diabetic patients: a cross sectional hospital based study, Addis Ababa, Ethiopia. BMC Res. Note. 2015;4(1):1–8. pmid:25635244
  20. 20. Bonger Z, Shiferaw S, Tariku EZJPp, adherence. Adherence to diabetic self-care practices and its associated factors among patients with type 2 diabetes in Addis Ababa, Ethiopia. Patient Prefere. Adherence. 2018;12:963.
  21. 21. Mohammed AS, Adem F, Tadiwos Y, Woldekidan NA, Degu AJD, Metabolic Syndrome, et al. Level of Adherence to the Dietary Recommendation and Glycemic Control Among Patients with Type 2 Diabetes Mellitus in Eastern Ethiopia: A Cross-Sectional Study. Diabetes Metab Syndr Obes: Targets and Therapy 2020;13:2605.
  22. 22. Dagnew B, Debalkie Demissie G, Abebaw Angaw DJE-BC, Medicine A. Systematic Review and Meta-Analysis of Good Self-Care Practice among People Living with Type 2 Diabetes Mellitus in Ethiopia: a national Call to Bolster Lifestyle Changes. Evid.- Complemet. Altern. Med. 2021;2021. pmid:33688368
  23. 23. Moher D, Liberati A, Tetzlaff J, Altman DG, med PGJP. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Ann. Inten. Med. 2009;6(7):e1000097.
  24. 24. Shamseer L, Moher D, Clarke M, Ghersi D, Liberati A, Petticrew M, et al. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015: elaboration and explanation. Bmj. 2015;349. pmid:25555855
  25. 25. Rajasekhar A, Lottenberg R, Lottenberg L, Liu H, Ang D. Pulmonary embolism prophylaxis with inferior vena cava filters in trauma patients: a systematic review using the meta-analysis of observational studies in epidemiology (MOOSE) guidelines. Journal of thrombosis and thrombolysis. 2011;32(1):40–6. pmid:21221716
  26. 26. Stang AJEjoe. Critical evaluation of the Newcastle-Ottawa scale for the assessment of the quality of nonrandomized studies in meta-analyses. Eur. J. Epidemiol. 2010;25(9):603–5. pmid:20652370
  27. 27. Hoy D, Brooks P, Woolf A, Blyth F, March L, Bain C, et al. Assessing risk of bias in prevalence studies: modification of an existing tool and evidence of interrater agreement. J. Clin. Epidemiol. 2012;65(9):934–9. pmid:22742910
  28. 28. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. Bmj. 2003;327(7414):557–60. pmid:12958120
  29. 29. Cumpston M, Li T, Page MJ, Chandler J, Welch VA, Higgins JP, et al. Updated guidance for trusted systematic reviews: a new edition of the Cochrane Handbook for Systematic Reviews of Interventions. Cochrane Database Syst Rev. 2019;10:ED000142. pmid:31643080
  30. 30. Huedo-Medina TB, Sánchez-Meca J, Marín-Martínez F, Botella J. Assessing heterogeneity in meta-analysis: Q statistic or I2 index? Psychol methods. 2006;11(2):193.
  31. 31. Borenstein M, Hedges LV, Higgins JP, Rothstein HR. A basic introduction to fixed‐effect and random‐effects models for meta‐analysis. ReS.Synth. Methods. 2010;1(2):97–111.
  32. 32. Thompson SG, Higgins JP. How should meta‐regression analyses be undertaken and interpreted? Stat. Med. 2002;21(11):1559–73.
  33. 33. G R-G. Detecting publication bias in random effects meta-analysis: An empirical comparison of statistical methods. 2006.
  34. 34. Ayele BH, Mengesha MM, Tesfa T. Predictors of self-care activities of outpatient diabetic residents in Harar and Dire Dawa: A hospital-based cross-sectional study. SAGE open Med. 2019; 7:2050312119865646. pmid:31384462
  35. 35. Hailu E, Mariam WH, Belachew T, Birhanu Z. Self-care practice and glycaemic control amongst adults with diabetes at the Jimma University Specialized Hospital in south-west Ethiopia: A cross-sectional study. Afr.J.Prim. Health Care. Fam.Med. 2012;4(1).
  36. 36. Gurmu Y, Gela D, Aga F. Factors associated with self-care practice among adult diabetes patients in West Shoa Zone, Oromia Regional State, Ethiopia. BMC Health Serv. Res. 2018;18(1):1–8.
  37. 37. Woldu MA, Wami CD, Lenjisa J, Tegegne G, Tesafye G, Dinsa H. Factors associated with poor glycemic control among patients with type 2 diabetes mellitus in Ambo Hospital, Ambo; Ethiopia. Endocrinol Metab Synd. 2014;3(143):2161–1017.1000143.
  38. 38. Zinab B, Debalke R. Acute glycemic level and its association with physical activity recommendation among type 2 diabetic patients in Illubabor zone oromiya, Ethiopia Int. J. Nutr. Metab. 2019;11(1):1–10.
  39. 39. Daba A, Yazew T. Associated Factors with Knowledge, Attitude and Practices of Type II Diabetic Patients in Ambo University Referral Hospital, Ethiopia. Am. J. Lab. Med. 2020;5(4):102–12.
  40. 40. Fekadu G, Bula K, Bayisa G, Turi E, Tolossa T, Kasaye H. Challenges and factors associated with poor glycemic control among type 2 diabetes mellitus patients at Nekemte Referral Hospital, Western Ethiopia. J. Multidiscip. Healthc. 2019;12:963. pmid:31819470
  41. 41. Debalke R. Non-adherence to dietary and physical activity recommendations and associated factors among type 2 diabetic patients on follow up in government hospitals of Ilu Bbba bora zone, Oromia region, Ethiopia. Public Health Science (Thesis). Jimma, Jimma University; 2018.
  42. 42. Lemesa F. Assessment of self-care practices and associated factors among type 2 diabetic patients at Tikur Anbessa specialized hospital Addis Ababa, Ethiopia(doctoral dessetation, Addis Ababa University). 2014.
  43. 43. Berhe KK, Demissie A, Kahsay AB, Gebru HB. Diabetes self care practices and associated factors among type 2 diabetic patients in Tikur Anbessa specialized hospital, Addis Ababa, Ethiopia-a cross sectional study. Int.J.Pharm.Sci Res. 2012;3(11):4219.
  44. 44. Halima MI, Fisseha Z, Tarkie AW, Abere WA. Knowledge, Practice, and its Associated Factors of Type 2 Diabetic Patients towards Dietary Therapy at University of Gondar Specialized Hospital, Northwest, Ethiopia 2017. J Diabetes Clin Prac. 2019;3(109).
  45. 45. Mekonnen CK, Ferede YM, Abate HK. Determinants of Dietary Adherence Among Type 2 Diabetes Patients Aimed COVID-19 at the University of Gondar Comprehensive Specialized Hospital. Diabetes, Metab SyndrObes: Targets and Therapy. 2021;14(917). pmid:33688226
  46. 46. Sorato MM, Tesfahun C, Lamessa D. Levels and predictors of adherence to self-care behaviour among adult type 2 diabetics at Arba Minch general hospital, Southern Ethiopia. J Diabetes Metab. 2016;7(6):11.
  47. 47. Degefa G, Wubshet K, Tesfaye S, Hirigo AT. Predictors of Adherence Toward Specific Domains of Diabetic Self-Care Among Type-2 Diabetes Patients. Clin. Med. Insights: Endocrinol. Diabetes. 2020;13:1179551420981909. pmid:33424232
  48. 48. Getie A, Geda B, Alemayhu T, Bante A, Aschalew Z. Self-care practices and associated factors among adult diabetic patients in public hospitals of Dire Dawa administration, Eastern Ethiopia. BMC Public Health. 2020;20(1):1–8.
  49. 49. Berhe KK, Gebru HB, Kahsay HB, Kahsay AA. Assessment of self care management and its associated factors among type 2 diabetes patients in Mekelle Hospital and Ayder Referral Hospitals, Mekelle City, Tigray, Northern Ethiopia, 2012/13. Glob. J. Med. Res. 2017;17(1):2249–4618.
  50. 50. Marinho FS, Moram C, Rodrigues PC, Leite NC, Salles GF, Cardoso CR. Treatment adherence and its associated factors in patients with type 2 diabetes: results from the Rio de Janeiro type 2 diabetes cohort study. J. Diabetes Res. 2018;2018.
  51. 51. Faria HTG, Rodrigues FFL, Zanetti ML, Araújo MFMd, Damasceno MM. Factors associated with adherence to treatment of patients with diabetes mellitus. ACTA Paul. Enferm. 2013;26(3):231–7.
  52. 52. Mumu SJ, Saleh F, Ara F, Afnan F, Ali L. Non-adherence to life-style modification and its factors among type 2 diabetic patients. Indian journal of public health. 2014;58(1):40–4. pmid:24748356
  53. 53. Mirahmadizadeh A, Khorshidsavar H, Seif M, Sharifi MH. Adherence to medication, diet and physical activity and the associated factors amongst patients with type 2 diabetes. Diabetes Ther. 2020;11(2):479–94. pmid:31916213
  54. 54. Zanchim MC, Kirsten VR, Marchi AC. Consumption of dietary intake markers by patients with diabetes assessed using a mobile application. Ciência & Saúde Coletiva. 2018;23:4199–208.
  55. 55. Afroz A, Ali L, Karim MN, Alramadan MJ, Alam K, Magliano DJ, et al. Glycaemic Control for People with Type 2 Diabetes Mellitus in Bangladesh-An urgent need for optimization of management plan. Sci. Rep. 2019;9(1):1–10.
  56. 56. Mostafavi‐Darani F, Zamani‐Alavijeh F, Mahaki B, Salahshouri A. Exploring the barriers of adherence to dietary recommendations among patients with type 2 diabetes: A qualitative study in Iran. Nurs. Open. 2020;7(6):1735–45. pmid:33072357
  57. 57. Tsega G, Getaneh G, Taddesse G. Are Ethiopian diabetic patients protected from financial hardship? PloS One. 2021;16(1):e0245839. pmid:33503048
  58. 58. Gebru M, Remans R, Brouwer ID, Baye K, Melesse MB, Covic N, et al. Food systems for healthier diets in Ethiopia: Toward a research agenda. IFPRI Discussion Paper. 2018.
  59. 59. Dereje N, Bekele G, Nigatu Y, Worku Y, Holland RP. Glycemic index and load of selected ethiopian foods: an experimental study. J. Diabetes Res. 2019;2019. pmid:31950066
  60. 60. Khazrai YM, Defeudis G, Pozzilli P. Effect of diet on type 2 diabetes mellitus: a review. Diabetes Metab. Res. Rev.2014;30(S1):24–33. pmid:24352832
  61. 61. Turner-McGrievy GM, Barnard ND, Cohen J, Jenkins DJ, Gloede L, Green AA. Changes in nutrient intake and dietary quality among participants with type 2 diabetes following a low-fat vegan diet or a conventional diabetes diet for 22 weeks. J. Am. Diet. Assoc. 2008;108(10):1636–45.
  62. 62. World Health Organization. Improving adherence rates: Guidance for countries. Chapter V: The magnitude of the problem of poor adherence. .2003:2006.
  63. 63. Luo X, Liu T, Yuan X, Ge S, Yang J, Li C, et al. Factors influencing self-management in Chinese adults with type 2 diabetes: a systematic review and meta-analysis. International journal of environmental research and public health. 2015;12(9):11304–27. pmid:26378555
  64. 64. Abreu dD, Guessous I, Vaucher J, Preisig M, Waeber G, Vollenweider P, et al. Low compliance with dietary recommendations for food intake among adults. Clinical nutrition 2013, 32(5):783–788. pmid:23260749
  65. 65. RobatSarpooshi D, Mahdizadeh M, Siuki HA, Haddadi M, Robatsarpooshi H, Peyman N. The Relationship Between Health Literacy Level and Self-Care Behaviors in Patients with Diabetes. Patient Related Outcome Measures. 2020;11:129–35. pmid:32440244
  66. 66. Letta S, Aga F, Yadeta TA, Geda B, Dessie Y. Barriers to diabetes patients’ self-care practices in Eastern Ethiopia: A qualitative study from the health care providers perspective. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2021;14:4335. pmid:34712054
  67. 67. Brown AF, Ettner SL, Piette J, Weinberger M, Gregg E, Shapiro MF, et al. Socioeconomic position and health among persons with diabetes mellitus: a conceptual framework and review of the literature. Epidemiologic reviews. 2004 Jul 1;26(1):63–77. pmid:15234948
  68. 68. Bonaccio M, Bonanni AE, Di Castelnuovo A, De Lucia F, Donati MB, De Gaetano G, et al. Low income is associated with poor adherence to a Mediterranean diet and a higher prevalence of obesity: cross-sectional results from the Moli-sani study. BMJ open. 2012 Jan 1;2(6):e001685. pmid:23166131
  69. 69. French SA, Tangney CC, Crane MM, Wang Y, Appelhans BM. Nutrition quality of food purchases varies by household income: the SHoPPER study. BMC public health. 2019 Dec;19(1):1–7.
  70. 70. Barbosa LB VS, Correia LO, Ferreira RC. Nutrition knowledge assessment studies in adults: a systematic review. Cien Saude Colet. 2016;21:149–62. pmid:26910153
  71. 71. Halali F MR, Mobasseri M, Jafarabadi MA, Avval SK. Perceived barriers to recommended dietary adherence in patients with type 2 diabetes in Iran. Eat. behav. 2016:205–10. pmid:26994360
  72. 72. Maillot M VF, Delaere F, Lluch A, Darmon N. Dietary changes needed to reach nutritional adequacy without increasing diet cost according to income: an analysis among French adults. PloS one. 2017;12(3):e0174679. pmid:28358837
  73. 73. Cavaliere A DME, Banterle A. Exploring the adherence to the Mediterranean diet and its relationship with individual lifestyle: the role of healthy behaviors, pro-environmental behaviors, income, and education. Nutrients. 2018;10(2):141.
  74. 74. Han CY, Chan CG, Lim SL, Zheng X, Woon ZW, et al. Diabetes-related nutrition knowledge and dietary adherence in patients with Type 2 diabetes mellitus: A mixed-methods exploratory study. Proceedings of Singapore Healthcare. 2020 Jun;29(2):81–90.
  75. 75. Piri AR. Effects of education based on health belief model on dietary adherence in diabetic patients. Journal of Diabetes and Metabolic Disorders. 2010;9:15.
  76. 76. Hu X, Zhang Y, Lin S, Guo X, Yang D, Cai M, Gao L. Dietary knowledge, attitude and practice (KAP) among the family members of patients with type 2 diabetes mellitus (T2DM) and its influence on the KAP of T2DM patients. Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy. 2021;14:205.
  77. 77. Alexander A, Sureshkumar AD, Jones M, Marais D. 8 Do nutrition education programmes improve health outcomes in patients with chronic diseases? A systematic review.
  78. 78. Siopis G, Colagiuri S, Allman-Farinelli M. People with type 2 diabetes report dietitians, social support, and health literacy facilitate their dietary change. Journal of Nutrition Education and Behavior. 2021 Jan 1;53(1):43–53. pmid:33077370
  79. 79. Merino J. Precision nutrition in diabetes: when population-based dietary advice gets personal. Diabetologia. 2022 May 20:1–0. pmid:35593923
  80. 80. Taylor MK, Sullivan DK, Ellerbeck EF, Gajewski BJ, Gibbs HD. Nutrition literacy predicts adherence to healthy/unhealthy diet patterns in adults with a nutrition-related chronic condition. Public health nutrition. 2019 Aug;22(12):2157–69. pmid:31146797