An interventional study of The 5Ad Diet and The Low FODMAP Diet in Functional Bowel Disorder, Irritable Bowel Syndrome and Food Intolerance, sponsored by University of Suffolk. Completed at 1 site in United Kingdom. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-11-24.
Sponsored by University of Suffolk · Not applicable, Interventional, and Treatment
The goal of this randomised controlled trial (RCT) is to compare the efficacy of the newly developed 5Ad diet against the widely researched low fermentable oligo-, di-, monosaccharide and polyols (FODMAP) diet in reducing gastrointestinal symptoms associated with functional bowel disorders/food intolerances.
The primary aims of this RCT are to determine:
To achieve the above aims, an RCT will be conducted with the 5Ad diet in one arm vs the active phase of the low FODMAP diet in the other arm, in a cross-over design with a 7 days washout phase in between. Both dietary protocols will be followed by each participant for 7 days.
Researchers will compare the results from the 2 dietary protocols in order to ascertain the superiority of one over the other in regards to 6 gastrointestinal symptoms (abdominal pain, bloating, flatulence, bowel urgency, straining and incomplete defecation), stool form and frequency of defecation.
Functional Bowel Disorders (FBDs) are characterised by chronic gastrointestinal symptoms including abdominal pain, constipation, bloating, diarrhoea, alternating abdominal symptoms, and irregular frequency of bowel movements among others in the absence of any intestinal abnormality. The prevalence of FBDs ranges from 15 - 20% worldwide, with remarkable economic burden on health systems and significant impact on the quality of life of sufferers. It is estimated that between 60% - 89% of individuals that suffer from FBDs find that foods exacerbate their symptoms. Therefore, dietary therapies are frequently implemented to assist with symptom relief in these individuals.
Although the low FODMAP diet is the most commonly followed diet for the treatment of FBDs, there are concerns regarding it's complexity, restrictiveness, nutritional adequacy, and effectiveness. Therefore, the 5Ad diet was designed to fill a gap in the existing research and to overcome the limitations associated with existing dietary approaches.
Preliminary findings from the first study in 2019 suggested that the 5Ad diet might be a promising universal approach for varying forms and severities of FBDs. Therefore, an RCT is needed to substantiate these previous results. Thus, this RCT aims to determine whether the 5Ad diet is at least as effective as the low FODMAP diet in reducing gastrointestinal symptoms associated with FBDs/food intolerances.
1,062 studies on the registry are indexed under Irritable Bowel Syndrome; 190 are open to participants now.
This study's enrollment of 52 is below the median of 71 across 853 interventional studies indexed under Irritable Bowel Syndrome.
Browse Irritable Bowel Syndrome studies →This is the only study on the registry with University of Suffolk as lead sponsor.
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Individuals are eligible for the study if all of the following criteria are met:
Exclusion Criteria:
Individuals are excluded from the study if any of the following criteria are met:
Participants are required to follow the 5Ad diet for 7 days, followed by a washout phase for 7 days, before crossing over to the active phase of the low FODMAP diet for 7 days.
Other: The 5Ad Diet · Other: The Low FODMAP Diet
Participants are required to follow the active phase of the low FODMAP diet for 7 days, followed by a washout phase for 7 days, before crossing over to the 5Ad diet for 7 days.
Other: The 5Ad Diet · Other: The Low FODMAP Diet
Participants are to follow the 5Ad diet.
Participants are to follow the active phase of the Low FODMAP diet.
Abdominal Pain
Abdominal pain will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Abdominal Bloating
Abdominal bloating will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Flatulence
Flatulence will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Bowel Urgency
Bowel urgency will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Straining
Straining will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Incomplete Defecation
Incomplete defection will be recorded daily in a symptom diary and measured using a 4 point Likert-type scale, coded from 0 - 10 for conversion into continuous variables (None = 0; Mild = 1 - 3; Moderate = 4 - 6 ; Severe = 7 - 10).
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Stool Form
Stool form will be measured using the Bristol Stool Form Scale. Type 1 - Separate hard lumps, like nuts (hard to pass), Type 2 - Sausage shaped, but lumpy, Type 3 - Like a sausage but with cracks on its surface, Type 4 - Like a sausage or snake, smooth and soft, Type 5 - Soft blobs with clear cut edges (passed easily), Type 6 - Fluffy pieces with ragged edges, a mushy stool, and Type 7 - Watery, no solid pieces, entirely liquid. Stool Types 1 and 2 are associated with constipation, while stool Types 5 - 7 are associated with diarrhoea. Stool Types 3 and 4 are considered normal stools.
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Frequency of defecation
Frequency of defecation will be recorded daily in a symptom diary.
Time frame: Assessed daily throughout both dietary protocols (7 days for each dietary protocol)
Fatigue
Fatigue will be recorded and measured using the Fatigue Assessment Scale (FAS) (Michielsen et al., 2003), using a 5 point Likert-type scale, coded from 1 - 5 for conversion into continuous variables (None = 1; Sometimes = 2; Regularly = 3; Often = 4; Always = 5). Question 1 - I am bothered by fatigue; Question 2 - I get tired very quickly; Question 3 - I don't do much during the day; Question 4 - I have enough energy for everyday life; Question 5 - Physically, I feel exhausted; Question 6 - I have problems starting things; Question 7 - I have problems thinking clearly; Question 8 - I feel no desire to do anything; Question 9 - Mentally, I feel exhausted and Question 10 - When I am doing something, I can concentrate quite well. Question 4 and 10 are to be reverse scored. Total scores can range from 10, indicating the lowest level of fatigue, to 50, denoting the highest.
Time frame: Assessed on the last day of both dietary protocols (Day 7 of each dietary protocol)
Mental Fatigue
Mental fatigue will be measured using the Fatigue Assessment Scale (FAS), using a 5 point Likert-type scale, coded from 1 - 5 for conversion into continuous variables (None = 1; Sometimes = 2; Regularly = 3; Often = 4; Always = 5). Only questions 6 - 10 will be used to calculate the mental fatigue score. Question 6 - I have problems starting things; Question 7 - I have problems thinking clearly; Question 8 - I feel no desire to do anything; Question 9 - Mentally, I feel exhausted and Question 10 - When I am doing something, I can concentrate quite well. Question 10 is to be reverse scored. Total scores can range from 5, indicating the lowest level of fatigue, to 25, denoting the highest.
Time frame: Assessed on the last day of both dietary protocols (Day 7 of each dietary protocol)
Physical Fatigue
Physical fatigue will be measured using the Fatigue Assessment Scale (FAS), using a 5 point Likert-type scale, coded from 1 - 5 for conversion into continuous variables (None = 1; Sometimes = 2; Regularly = 3; Often = 4; Always = 5). Only questions 1 - 5 will be used to calculate the mental fatigue score. Question 1 - I am bothered by fatigue; Question 2 - I get tired very quickly; Question 3 - I don't do much during the day; Question 4 - I have enough energy for everyday life; Question 5 - Physically, I feel exhausted. Question 4 is to be reverse scored. Total scores can range from 5, indicating the lowest level of fatigue, to 25, denoting the highest.
Time frame: Assessed on the last day of both dietary protocols (Day 7 of each dietary protocol)
This study is completed, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.
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