KNOWLEDGE AND BEHAVIORS SURROUNDING A GLUTEN‐FREE DIET BETWEEN MEDICALLY AND SELF‐DIAGNOSED INDIVIDUALS
Authors: Quinteros Sara Andrea 
Published: November 2023

Objective

Gluten, a protein found in wheat, rye and barley has been linked to the inflammatory response of the GI tract in individuals with Celiac Disease (CD), non‐celiac gluten sensitivity (NCGS), and in some cases irritable bowel syndrome (IBS). In recent years, several factors have contributed to the increase in these gluten‐related disorders, including improved medical diagnosis, public awareness of the disease, changes in the composition of wheat due to modern agricultural technologies and perceived health benefits from following a gluten‐free diet (GFD). However, little information exists about the relation between knowledge, behavior and nutritional consequences of a GFD. The purpose of this research was to examine the knowledge, behaviors and adherence to a gluten‐free diet by individuals with a medical diagnosis versus those who self‐diagnose themselves, and the nutritional consequences of following a gluten‐free diet.

Method

Participants responded to online questionnaires about knowledge (5 questions), purchasing behaviors (6 questions), adherence (6–7 questions) and dietary behaviors following a GFD (4 questions). Mean scores for knowledge, purchasing behaviors, adherence and changes in dietary patterns were calculated using independent‐samples t‐tests, ANOVAs and cross‐tabulations.

Results

In this largely female (82%) non‐Hispanic white (80%) sample, 63% reported to be self‐diagnosed with a GFD and 37% were medically diagnosed with CD, NCGS or IBS. Those with a medical diagnosis had statistically significant differences in knowledge (p=0.01) and adherence (p=0.0001) scores, dieted more frequently (p=0.001) and reported higher protein intakes (p=0.04) than the self‐diagnosed group.

Conclusion

A GFD requires education and knowledge of gluten containing foods. Strict adherence of a GFD is challenging and may cause several nutritional deficiencies. However, a GFD can be wholesome and nutrient dense provided it is well planned under the supervision of a qualified healthcare professional.

Support or Funding Information

N/A

Diagnosis status of respondents to GFD survey

n
%

Diagnosis (n=73)

Medical Doctor
27
37

Self‐Diagnosed
46
63

Medical Diagnosis Category (n=24)*

Celiac Disease
9
12

Gluten Sensitivity
8
11

Irritable Bowel Syndrome
7
10

Other Health Professional (n=3)**

Chiropractor
2
66.7

Acupuncturist
1
33.3

Percentages do not add up to 100% because there were other categories in the question that were excluded from analysis

All diagnosed with gluten sensitivity

Cross‐tabulation

Correlation analysis regarding reasons for following a gluten‐free diet by surveyed participants

Medical
Social

I feel better when I eat gluten‐free
I was told to eat gluten‐free by a doctor
My friends eat gluten‐free
My family eats gluten‐free
News/TV/Media says gluten‐free is good
Social Media says gluten‐free is good
Health Reasons
Weight‐loss

Medical
I fee better when I eat gluten‐free
1
0.165
−0.004
0.114
0.166
0.116
0.430c
−0.073

I was told to eat gluten‐free by a doctor
0.165
1
−0.209
−0.173
0.061
0.168
0.322b
−0.018

Social
My friends eat gluten‐free
−0.004
−0.209
1
−0.139
−0.050
−0.035
−0.063
−0.159

My family eats gluten‐free
−0.114
−0.173
−0.139
1
0.141
0.253c
−0.195
0.100

News/TV/Media says gluten‐free is good
0.166
0.061
−0.050
0.141
1
0.702c
0.021
0.114

Social Media says gluten‐free it good
0.116
0.168
−0.035
0.253a
0 702c
1
0.133
0.222

Health Reasons
0.430c
0.322b
−0.063
−0.195
0.021
0.133
1
−0.001

Weight‐loss
−0.073
−0.018
−0.159
0.100
0.114
0.222
−0.001
1

n=73

Bivariate correlation analysis statistical significance p<0.05

Bivariate correlation analysis statistical significance p<0 01

Bivariate correlation analysis statistical significance p<0.001

Mean gluten knowledge scores for survey participants following a GFD

Medical Diagnosis (n=27)
Self‐Diagnosis (n=41)

Knowledge Score (n=68)

p‐value (p <0.05)

Mean ± St. Dev.
34.63 ± 4.70
31.41 ± 5.01
0.01a

Knowledge Scores
n
%
n
%
0.009b

100% (43)
0
0
0
0

90–99% (39–42)
6
22.2
5
12.2

80–89.9% (35–38)
10
37.0
6
14.6

70–79.9% (31–34)
6
22.2
10
24.4

60–69.9% (26–30)
3
11.1
16
39.1

50–59.9% (22–25)
2
7.4
3
7.3

0–49.9% (0–21)
0
0
1
2.4

n=68

Independent sample t‐test statistical significance p<0.05 @95% confidence level

Mann‐Whitney U test statistical significance p<0.05

Mean dieting history of survey participants

Medical Diagnosis (n=27)
Self‐Diagnosis (n=46)

Dieting History (n=73)

p‐value (p <0.05)

Mean ± St. Dev.
1.7±1.07
0.91±0.86
0.001a

Dieting Score
n
%
n
%
0.001b

0=Never dieted
3
11.1
15
32.6

1 =Once/Follow one diet
9
33.3
23
50.0

2–4 = Different Times/Diets
15
55.5
8
17.4

Independent‐samples t‐test statistical significance p<0.05 @95% confidence level

Mann‐Whitney U test statistical significance p<0.05

Changes in dietary patterns as reported by survey participants following a GFD

Medical Diagnosis (n=23)
Self‐Diagnosis (n=33)

Mean ± St. Dev.
Increased N (%)
Stayed the Same N (%)
Decreased N (%)
Mean ± St. Dev.
Increased N (%)
Stayed the Same N (%)
Decreased N (%)
p‐value (p<0.05)

Food Groups

Proteins
2.43 ± 0.662
12 (52.2)
9 (39.1)
2 (8.7)
2.09 ± 0.579
7 (21.2)
22 (66.7)
4 (12.1)
0.04a0.033b

Dairy
1.96 + 0.706
5 (21.7)
12 (52.2)
6 (26.1)
2.03 ± 0.684
8 (24.2)
18 (54.5)
7 (54.5)
NS*

Carbs
1.30 ± 0.635
2 (8.7)
3 (13.0)
18 (78.3)
1.24 ± 0.435
0 (0.0)
8 (24.2)
25 (75.8)
NS*

Fruits and Vegetables
2.65 ± 0.487
15 (65.2)
8 (34.8)
0 (0.0)
2.61 ± 0.496
20 (60.6)
13 (39.4)
0 (0.0)
NS*

Fats
1.87 ± 0.694
4 (17.4)
12 (52.2)
7 (30.4)
1.85 ± 0.619
4 (12.1)
20 (60.6)
9 (27.3)
NS*

Sweets
1.52 ± 0.730
3 (13.0)
6 (26.1)
14 (60.9)
1.30 ± 0.467
0 (0.0)
10 (30.3)
23 (69.7)
NS*

n=56

Independent sample t‐test statistical significance p<0.05 @95% confidence level

Mann‐Whitney U test statistical significance p<0.05

NS=not significant

3‐point Likert scale

Mean adherence and quality of life scores for survey participants following a GFD

Medical Diagnosis (n=27)
Self‐Diagnosis (n=46)

Total Adherence

p‐value (p <0.05)

Mean ± St. Dev.
5.74±4.83
1.67±3.09
0.0001a0.001b

Adherence Score
n
%
n
%

12 (100%)
1
3.7
0
0.0

11 (90%)
5
18.5
1
2.2

10 (80%)
4
14.8
2
4.3

9 (70%)
3
11.1
1
2.2

8 (60%)
0
0.0
1
2.2

6–7 (50%)
1
3.7
1
2.2

5 (40%)
2
7.4
1
2.2

4 (30%)
0
0.0
0
0.0

3 (20%)
0
0.0
1
2.2

2 (10%)
1
3.7
4
8.7

1 (1–9.9%)
2
7.4
7
15.2

0 (0%)
8
29.6
27
58.7

Quality of life Score

0 = “Excellent”
13
48.1
22
47.8

1 = “Good”
7
25.9
21
45.7

2 = “Average”
7
25.9
3
6.5

3 = “Poor”
0
0.0
0
0.0

Mean ± St. Dev.
0.78±0 85
0.59±0.62

n‐73

Independent sample t‐test statistical significance p<0.001 @95% confidence level

Mann‐Whitney U test statistical significance p<0.001

Mean adherence score

Celiac Disease
Gluten Sensitivity
Irritable Bowel Syndrome

Total Adherence

p‐value (p <0.05)

Mean ± St. Dev.
8.89±3.89
5.00±4.72
2.14±3.53
0.012a0.010b

One‐way analysis of variance (ANOVA) statistical significance p<0.05

Post Hoc Tests statistical significance between Celiac Disease and Irritable Bowel Syndrome p<0.05