Dietary beliefs and recommendations in inflammatory bowel disease: a national survey of healthcare professionals in the UK

Abstract

Background

The role of diet in inflammatory bowel disease (IBD) remains incompletely understood. Knowledge around the actual dietary advice healthcare professionals provide to individuals with IBD is scarce. Our objective was to describe the dietary beliefs of healthcare professionals and dietary recommendations made to people with IBD.

Methodology

An online survey regarding IBD-related dietary beliefs and advice provided to patients was distributed to gastroenterologists, dietitians and IBD nurses in the UK.

Results

Two-hundred and twenty-three eligible healthcare professionals participated: 107 (48%) believed that diet was involved in IBD development. The most frequently implicated dietary components were processed foods (78%), additives/preservatives (71%), sweet/sugary foods (36%), red meat (36%) and fatty foods (31%). Views were broadly consistent across professions, however, gastroenterologists were significantly more likely to believe red meat and additives/preservatives initiated IBD. One hundred and thirteen participants (53%) believed that diet could trigger disease relapse and 128 (61%) recommended limiting specific foodstuffs to reduce this risk, most commonly high fibre foods. Forty-six (23%) considered recommending a low Fermentable Oligo-, Di- and Monosaccharides and Polyols diet to reduce relapse risk. IBD nurses and healthcare professionals with <5 years experience were most likely to recommend this. Dietitians felt most comfortable providing dietary advice for functional gastrointestinal symptoms in quiescent IBD.

Conclusion

Dietary advice in IBD is inconsistent reflecting uncertainty among healthcare professionals. While some consensus exists regarding dietary components implicated in IBD development and relapse, dietary recommendations varied. Future research is required to disentangle these complex relationships, alongside better training and education.

Key messages.

What is already known about this subject?

• Epidemiological studies have implicated diet in the development of inflammatory bowel disease (IBD) but the role of specific dietary components in the aetiology and management of IBD remains incompletely understood.

• Recent dietary guidance from the International Organisation for the Study of IBD has recommended that it may be prudent to increase exposure to fruit and vegetables in Crohn’s disease, reduce intake of red and processed meat in ulcerative colitis and reduce specific dietary fats, additives and emulsifiers in both forms of IBD.

• There is currently no convincing evidence for the use of whole food exclusion diets in maintenance of remission in IBD but a low Fermentable Oligo-, Di- and Monosaccharides and Polyols diet has been shown to improve functional gastrointestinal symptoms in people with inactive IBD.

What are the new findings?

• While beliefs regarding specific dietary triggers for IBD development and relapse were broadly similar among professions, dietary advice regarding food consumption and avoidance was inconsistent.

• Avoidance or reduction of high fibre foods was frequently recommended by healthcare professionals to reduce the risk of IBD relapse, despite guidance that this should only be the case in those with symptomatic, stricturing Crohn’s disease.

Key messages.

How might it impact on clinical practice for the foreseeable future?

• Consideration must be given to how structured education and training programmes can be delivered to allied healthcare professionals managing people living with inflammatory bowel disease. In this way consensus, evidence-based, dietary knowledge and guidance can be appropriately disseminated allowing for more consistent recommendations to patients.

Introduction

Although epidemiological associations have implicated the western diet in the development of inflammatory bowel disease (IBD) the complexities surrounding the true role of diet remain incompletely understood.^{1 2} Diet is of interest to people with IBD and their healthcare professionals (HCPs) because of its importance in health and the role food plays in psychosocial well-being.^{3 4} Furthermore, individuals with IBD are at risk of nutritional deficiencies due to alterations in dietary behaviours, malabsorption and losses through the inflamed gut.^{3 5–8}

The relative dearth of credible evidence regarding diet and perceived indifference from HCPs can cause frustration among individuals with IBD. This risks people seeking information from other sources, leading to self-imposed dietary restriction with potential adverse consequences.3 5 9 10 The role of diet was recognised as a key research priority in a recent James Lind Alliance partnership exercise involving patients and clinicians.¹¹

Recently the International Organization for the Study of IBD published dietary guidance for IBD.¹¹ This recommended increasing exposure to fruit and vegetables in Crohn’s disease (CD), reducing intake of red and processed meat in UC and reducing specific dietary fats and additives in IBD.

Few data exist regarding the dietary advice actually provided by HCPs to individuals with IBD.^{12 13} The aim of our study was to describe dietary beliefs among HCPs and their dietary recommendations.

Materials and methods

Survey development

A 19-question survey was designed to collect responses from HCPs (gastroenterologists, IBD clinical nurse specialists (IBDCNS) and dietitians) regarding their beliefs about diet and IBD as well as recommendations regarding dietary prevention of disease relapse. Disease relapse/flare was defined as the development of active inflammation. The survey consisted of a combination of multiple-choice, free-text and Likert scales (online supplemental material).

Eligibility criteria

HCPs with a current licence to practise in the UK whose profession was either a gastroenterologist, IBDCNS or dietitian who manages people with IBD, were eligible to participate.

Study design

SurveyMonkey was used to distribute the survey via a web link to regional IBD leads across the UK who then shared this with their teams. A welcome message explained that implied consent was given through completion of the survey. All responses were anonymous.

Statistical analysis

IBM SPSS Statistics (V.25) was used with significance assessed at an α level of 0.05 (two sided). Descriptive statistics were used to define the respondents’ characteristics. Three potential predictors; respondent’s profession, number of patients seen per week and years in practice, were chosen as possible determinants for the variation observed in responses. Simple binary logistic regression was used to examine the relationship between predictors and outcomes of interest.

Results

Two-hundred and thirty-two HCPs responded of which 223 were eligible for inclusion (table 1). Nine were excluded due to not meeting inclusion criteria based on profession.

Table 1.

Respondent specifics (n=223)

Professional role
Consultant gastroenterologist	60 (27%)
Other gastroenterology doctor (registrar, associate specialist, clinical/research fellow, staff grade)	52 (23%)
IBDCNS	51 (23%)
Dietitian	60 (27%)
Workplace (choose all that apply)
Primary care	9 (4%)
DGH	96 (43%)
Tertiary care	41 (18%)
Teaching hospital	101 (45%)
Private practice	5 (2%)
Higher education institute	9 (4%)
Other (industry)	1 (0.4%)
Years in practice following professional certification
0 (still in training)	47 (21%)
<1 year	13 (6%)
1–4 years	45 (20%)
5–9 years	38 (17%)
10–19 years	55 (25%)
>20 years	25 (11%)
How many patients with IBD seen/week
0–5	66 (30%)
6–10	56 (25%)
11–15	33 (15%)
16–20	20 (9%)
>20	48 (22%)

DGH, District General Hospital; IBD, inflammatory bowel disease; IBDCNS, IBD clinical nurse specialists.

Beliefs regarding the role of diet in IBD development

One hundred and seven HCPs (48%) believed that dietary components were involved in the initial development of IBD and 78 (35%) were unsure. Respondents with <5 years experience were more likely to believe that diet was involved in IBD development than those who had practised for longer (p=0.002, OR 2.31, 95% CI 1.35 to 3.95). Dietary components most frequently reported are shown in figure 1.

Figure 1.

Dietary components believed by healthcare professionals to be involved in (A) the development of IBD and (B) triggering IBD relapse. IBD, inflammatory bowel disease.

Gastroenterologists were significantly more likely than IBDCNS and dietitians to believe red meat (IBDCNS: p=0.007, OR 6.13, 95% CI 1.63 to 22.72; dietitians: p=0.03, OR 3.23, 95% CI 1.13 to 9.17) and food additives/preservatives (IBDCNS: p=0.002, OR 5.56, 95% CI 1.85 to 16.67; dietitians: p=0.009, OR 4.08, 95% CI 1.42 to 11.62) played a role in IBD development.

Beliefs regarding the role of diet in IBD relapse

One hundred and thirteen (53%) believed that dietary components could play a role in triggering IBD relapse (ie, promote the development of intestinal inflammation). HCPs with <5 years since qualification were more likely than those with more experience to believe diet could trigger relapse (p=0.002, OR 2.34, 95% CI 1.35 to 4.06). Among HCPs who believed diet could contribute to IBD relapse (n=113), the most frequently reported components are shown in figure 1.

Beliefs regarding the role of specific dietary components in disease relapse did not vary based on profession, patients seen or years of experience with the exception of carbonated drinks. IBDCNS were significantly more likely than other HCPs (p<0.05) to believe carbonated drinks could cause disease relapse as were HCPs who saw >10 patients/week (p=0.03).

Dietary recommendations to prevent IBD relapse

One hundred and twenty-eight (61%) HCPs recommended the avoidance or limitation of certain dietary components to reduce relapse risk (10% always, 51% sometimes) (table 2). IBDCNS were more likely than gastroenterologists (77% vs 59%, p=0.03, OR 2.33, 95% CI 1.08 to 5.04) and dietitians (77% vs 50%, p=0.006, OR 3.36, 95% CI 1.41 to 7.99) to recommend dietary avoidance for these purposes.

Table 2.

Dietary components or supplements that HCPs advise people living with IBD to avoid, limit or consume in order to decrease the chance of an IBD flare/relapse (to prevent the development of active inflammation)

	n (% of HCPs)
Dietary component recommended to avoid or limit intake
High fibre	39 (19)*
Processed foods	31 (15)
Specific trigger foods identified by patient	21 (10)
Spicy foods	19 (9)
High fat diet	18 (9)
Alcohol	16 (8)
Caffeinated products (coffee, tea, energy drinks)	10 (5)
Milk products/high lactose	9 (4)
Red meat	9 (4)
Certain fruits and vegetables	8 (4)
High sugar	7 (3)
Carbonated drinks	4 (2)
Dietary component or supplement recommended to consume
Probiotics (eg, VSL3†)	17 (8)‡
Vitamin D (±calcium)	13 (6)
Low fibre/residue diet	13 (6)§
Oral nutritional supplements (eg, ensure, fortisips)	13 (6)
Curcumin/turmeric	10 (5)
Multivitamins	8 (4)
Omega three supplements or oily fish	6 (3)
Fruits and vegetables	5 (2)
Prebiotics/fibre	5 (2)

*4% of respondents specifically stated they would only advise limitation/avoidance of fibre in stricturing CD.

†2% of respondents specifically mentioned VSL#3 as the probiotic they would recommend.

‡1% of respondents specifically stated they would only recommend the use of probiotics in UC.

§1% of respondents specifically stated they would only recommend a low fibre/residue diet in stricturing CD.

CD, Crohn’s disease; HCPs, healthcare professionals; IBD, inflammatory bowel disease; UC, ulcerative colitis.

Ninety-eight (48%) recommended consuming specific foodstuffs or nutritional supplements to decrease relapse risk (42% occasionally, 6% always) (table 2).

Fifty-eight (29%) HCPs considered recommending a whole-food exclusion diet to decrease relapse risk. IBDCNS were significantly more likely than dietitians (41% vs 18%) to recommend an exclusion diet for this purpose (p=0.02, OR 3.15, 95% CI 1.23 to 8.01), as were HCPs with <5 years experience (37% vs 23%, p=0.03, OR 1.95, 95% CI 1.06 to 3.60).

Advice was highly variable. A low Fermentable Oligo-, Di- and Monosaccharides and Polyols (FODMAPs) diet was recommended by 23%, with IBDCNS being significantly more likely than gastroenterologists (p=0.01, OR 2.68, 95% CI 1.23 to 5.83) and dietitians (p=0.02, OR 3.31, 95% CI 1.25 to 8.71) to advise this. HCPs with <5 years experience were also more likely to recommend a low FODMAPs diet to decrease relapse risk (p=0.05, OR 2.0, 95% CI 1.02 to 3.93). Diets recommended less frequently included lactose-free (9%), anti-inflammatory (8%), gluten-free (6%), specific carbohydrate (2%) and palaeolithic (1%) (figure 2).

Figure 2.

Proportion of HCPs recommending specific whole food exclusion diets to people with IBD in order to try and reduce the chance of IBD flare/relapse. FODMAPs, Fermentable Oligo-, Di- and Monosaccharides and Polyols; HCPs, healthcare professionals; IBD, inflammatory bowel disease; IBDCNS, IBD clinical nurse specialists.

Functional gastrointestinal symptoms in IBD

One hundred and eighty (91%) HCPs believed diet could trigger functional gastrointestinal symptoms (FGS) in people with inactive IBD. Gastroenterologists were significantly more likely than IBDCNS (p=0.02, OR 4.78, 95% CI 1.32 to 17.24) and dietitians (p=0.01, OR 4.81, 95% CI 1.37 to 16.95) to hold these views.

Dietitians were significantly more likely to feel ‘relatively comfortable’ or ‘very comfortable’ providing dietary advice to reduce FGS in IBD than IBDCNS (90% vs 43%, p<0.001, OR 11.84, 95% CI 3.94 to 35.71) and gastroenterologists (90% vs 64%, p=0.001, OR 5.18, 95% CI 1.89 to 14.18) (figure 3). HCPs with >5 years experience also felt more comfortable providing such advice (p=0.005, OR 2.35, 95% CI 1.29 to 4.29).

Figure 3.

Responses regarding how comfortable HCPs felt providing dietary advice for the management of functional gastrointestinal symptoms in people with underlying inactive IBD. HCPs, healthcare professionals; IBD, inflammatory bowel disease; IBDCNS, IBD clinical nurse specialists.

Referral to a dietitian

Gastroenterologists and IBDCNS were either ‘likely’ (40%) or ‘very likely’ (35%) to refer someone with IBD to a dietitian and 5% reported referring all patients. Dietitian referrals were made for dietary advice on management of FGS in people with IBD (91%) and to address concerns regarding nutritional status or dietary intake (81%). Less commonly (20%), patients were referred for dietary advice on reducing IBD relapse risk.

Discussion

This is the first study to describe the dietary beliefs of IBD HCPs and the dietary advice they provide to people with IBD. Less than half believed that diet was involved in IBD development and the dietary components most frequently reported were those associated with a western diet.¹⁴ This perhaps reflects an increasing awareness of the potential role for the western diet in IBD development from epidemiological studies, yet to be fully supported by clinical data.^{1 14–17}

Interestingly, gastroenterologists were more likely to believe that red meat and food additives/preservatives were involved in IBD development. Some epidemiological studies have reported an association between preillness diets high in red meat and an increased risk of IBD development, however, this link has not been confirmed.^{14 15} Furthermore, specific additives and preservatives have been linked to mucosal inflammation and alterations in intestinal microbiota in some studies.¹⁸

When considering IBD relapse, again, many of the most frequently identified triggers were components of the western diet which have been potentially implicated in clinical studies.5 14 18–20 Other frequently reported triggers were spicy foods, carbonated drinks, alcohol, milk products, coffee and raw fruit and vegetables, all of which can cause gastrointestinal symptoms in people without IBD.^{3 21–24} This raises the question of whether HCPs genuinely believe that these dietary components contribute to IBD relapse or, rather, are exacerbating FGS.

Paradoxically, high fibre foods were identified by 31% as potentially contributing towards IBD relapse as well as being the dietary component that HCPs were most likely to recommend avoiding to prevent relapse. While guidelines recommend reduction of fibre intake in symptomatic, stricturing CD, reduction is not routinely advised in all individuals with IBD and is not known to reduce relapse risk.^{11 25 26} Instead, guidance suggests that it may be prudent to increase fruit and vegetables in CD.^{11 26} Furthermore, epidemiological studies suggest that preillness diets high in fibre may protect against CD, although this is not fully established.¹⁴ Irrational fibre restriction may adversely affect IBD-associated co-morbidities, such as metabolic syndrome and bowel cancer risk.²⁷

We acknowledge that some respondents may have been referring to the benefits of insoluble fibre restriction improving FGS in coexisting irritable bowel syndrome (IBS). Furthermore, a significant proportion of HCPs advised reduction of other dietary components such as spicy foods, caffeinated products, alcohol, milk products and certain fruits and vegetables, all of which can cause FGS. Given the frequent coexistence of IBS and food intolerances in IBD it is plausible that avoidance of these offers symptomatic benefit unrelated to IBD activity.^{28 29}

Other dietary components which HCPs recommended limiting included components of the western diet, namely processed foods, high fat foods and red meat. Recent guidance recommends reducing intake of these food groups and it is notable that the numbers in our study, who advise limiting these, were small.^{11 26}

With a striking lack of consistent dietary advice, it is not surprising that people with IBD frequently follow their own dietary rules. In accordance with the varied responses seen in our study, studies show that individuals with IBD frequently avoid a range of dietary components including spicy foods, fatty foods, alcohol, carbonated drinks, coffee, milk products and raw fruit and vegetables in order to prevent abdominal symptoms and disease relapse.3 5 10 30

Whole food exclusion diets have not been shown to be beneficial in the maintenance of remission in IBD and may put individuals at risk of nutritional deficiency.11 25 26 31 Despite this, 29% of respondents would consider recommending one to decrease relapse risk. Most frequently reported was a low FODMAPs diet, an intervention which has good evidence for managing IBS symptoms.³² This approach has also been recommended for managing FGS in people with quiescent IBD but there is currently no evidence for it maintaining remission.22 26 33 34 Current evidence highlights the need for a dietetic-led approach in implementing the FODMAP method and achieving beneficial outcomes.³⁵ In IBD, dietetic oversight of this intervention is perhaps more clinically relevant given the heightened risk of nutritional deficiency and impaired food-related quality of life.^{4 36}

Interestingly, IBDCNS were most likely to recommend a low FODMAPs diet but felt least comfortable providing dietary advice to manage FGS. Inconsistencies in how approaches are applied may relate to a lack of funding for specialist dietitians in gastroenterology nationally.³⁷ Furthermore, the lack of consensus between HCPs in our study reflects the dearth of credible dietary evidence and the need for broad-based education and training of HCPs.^{12 13}

A limiting factor in this study was the relatively small number of respondents to the survey despite wide dissemination across the UK. Despite this, an even distribution of responses among differing HCPs was achieved. The survey was specifically targeted at HCPs involved in the management of people with IBD. Responses are likely to be skewed towards those with an interest in IBD resulting in the potential for over-reporting or under-reporting compared with more general gastroenterology HCPs. Further response bias is acknowledged due to the multiple choice options in the survey not being exhaustive. The survey was disseminated via regional leads rather than national societies and the overall visibility of the survey among all gastroenterology HCPs within the UK was therefore unclear.

Conclusion

This is the first study providing evidence of conflicting beliefs and a lack of consensus regarding dietary recommendations among IBD HCPs. The study highlights the importance of establishing broad-based training programmes for allied HCPs involved with IBD thus allowing for dissemination of existing, evidenced-based, dietary guidance. Future dietary research must focus on disentangling the complexities of diet, gastrointestinal symptoms and intestinal inflammation.

Data availability statement

Data are available on reasonable request from the corresponding author.

Ethics statements

Patient consent for publication

Not required.

Ethics approval

The study was exempt from need for ethical review by the Health Research Authority.