The Effects of an Anti-inflammatory Dietary Consultation on Self-efficacy, Adherence and Selected Health Outcomes: A Randomized Control Trial

Abstract

Research has shown that an anti-inflammatory diet can reduce inflammation and improve health outcomes in individuals with neurological disability, however, long term adherence is challenging. This study aimed to determine the effects of a 2-part dietary consultation, targeted at identified barriers for adherence in this population, on self-efficacy for adhering to an anti-inflammatory diet, as well as adherence and health outcomes one-month post-intervention. Eleven individuals (10 female, age 51.5±12.6 years) with neurological disability (7 multiple sclerosis, 3 spinal cord injury, 1 muscular dystrophy; 20.5 ± 10.6 years post-injury/diagnosis) participated. The intervention group (n = 7) received recipes for an anti-inflammatory diet and the consultation, while controls (n = 4) received the recipes only. The consultation included a home-visit involving cooking and accessible kitchen equipment demonstrations, and an accompanied trip to the grocery store. Task and barrier self-efficacy improved immediately following the consultation with trends for improvement one-month post-intervention. The consultation was also associated with increased dietary adherence one-month post-intervention and decreased depressive symptoms. Changes in dietary adherence (r = −.61; P = .045), and barrier self-efficacy (r = −.77; P = .009) were negatively correlated to changes in depression. Thus, a consultation targeted at barriers related to anti-inflammatory eating can improve self-efficacy for adherence as well as actual adherence and depressive symptomology one-month later.

‘Participants were given strategies towards meal planning and preparation as well as the opportunity to use helpful accessible kitchen equipment’.

Introduction

Individuals with neurological disability such as spinal cord injury (SCI) and multiple sclerosis (MS) are often characterized by chronic inflammation and thus, present with an excess of pro-inflammatory mediators and reduced anti-inflammatory mediators in circulation compared to age-matched, healthy, able-bodied controls.^1-4 Individuals with either SCI or MS, can also be affected by many secondary health conditions that have been linked to a common inflammatory aetiology. These conditions include anxiety, depression,^5-7 neuropathic pain^8-10 and obesity^11,12 among others. Treatments that can effectively reduce inflammation can, by consequence, decrease or eliminate the prevalence and severity of the aforementioned secondary complications and are, therefore, extremely important to investigate. Accordingly, previous work from our lab showed that a 12-week anti-inflammatory diet was successful in reducing circulating pro-inflammatory cytokines as well as lowering self-reported neuropathic pain and depression.^13,14 Several other studies have adopted similar nutritional interventions to varied success.^15-17

However, long term adherence to specialized diets has proven to be very challenging. In the aforementioned studies by Allison and Ditor^13,14 participants were 87.5% compliant to the diet, but at one year follow-up compliance rates had dropped to 43%, with depression levels returning to baseline values as well. ¹⁸ A subsequent qualitative study identified several barriers to adherence including a lack of knowledge regarding meal planning and preparation and the expense of anti-inflammatory supplements. ¹⁹ In contrast, allowing oneself to have occasional ‘cheat days’ when participants strayed from the diet seemed to facilitate overall dietary adherence. ¹⁹ In addition to the study conducted by Bailey and colleagues, ¹⁹ other research has presented similar themes. Costs, lack of knowledge, low self-efficacy, disability-related fatigue and lack of motivation have repeatedly been identified as problematic factors in other research examining dietary behaviours and adherence in special populations.^20-22

To address the previously identified barriers and facilitators to dietary adherence our lab designed a modified version of the original anti-inflammatory diet called the Mad Dog diet. This newer version incorporated a 5-day per week meal plan rather than the original 7-day per week (to allow cheat days), eliminated the expensive anti-inflammatory supplements and replaced the lost micronutrients with whole foods, and included more palatable recipes created by professional chefs. We also designed a two-part dietary consultation, the Mad Dog consultation, that addressed the identified barriers of lack of knowledge regarding meal planning and preparation. Part I of this consultation entailed an accompanied trip to the participant’s grocery store to learn about shopping for value, reading nutrition labels and finding ingredients, while Part II of the consult entailed a cooking demonstration in the participant’s home and a demonstration of selected pieces of accessible kitchen equipment that may assist meal preparation in those with limited hand function.

Regarding the Mad Dog consultation, previous studies hoping to increase exercise adherence have used similar interventions with success in individuals with SCI. ²³ In this study, the researchers investigated if a single home-based consultation session (approximately 70 minutes long) could improve participants’ exercise self-efficacy and behaviours. Results showed that participant self-managed physical activity frequency and duration significantly increased following the consultation, as did their knowledge regarding exercise, and their task and barrier self-efficacy. ²³ Regarding the latter terms, task self-efficacy refers to one’s confidence in their ability to achieve of a specified task and it is often determined and expressed in increasing degrees of the task (confidence in completing 50%, 75% or 100% of the task). Barrier self-efficacy refers to one’s confidence in their ability to overcome the barriers associated with task achievement. Measuring confidence in this way can apply to any behaviour modification goal such as increasing activity, improving eating habits, smoking cessation and others. There is often overlap between the barriers and facilitators for regular exercise and those for long term dietary adherence, especially in those with physical disability. Therefore, it is reasonable to hypothesize that our Mad Dog consultation may also have positive effects of dietary self-efficacy, eating behaviours and health outcomes.

The primary purpose of this study was therefore, to determine if the two-part Mad Dog dietary consultation could increase task and barrier dietary self-efficacy in individuals with neurological disability, as well as improve long term dietary adherence to the Mad Dog diet. As a secondary purpose, we aimed to determine if putative increases in dietary adherence would have a positive impact on self-reported depression and neuropathic pain. These health outcomes were chosen as aforementioned work from our lab has shown them to improve following an anti-inflammatory diet intervention.^13,14

Methods

Participants

This study was a randomized, control trial and all participants were recruited from a university-based wheelchair exercise facility (Power Cord) at Brock University, Ontario, Canada or the MS Society of Canada research portal, via recruitment posters between November and December, 2021. To be eligible for this study, participants were required to be over 18 years of age, fluent in English and at least one year removed from either SCI or neurological diagnosis. All participants but one (who had muscular dystrophy) had either SCI or MS. Participants with SCI could have any level or severity of injury while participants with MS could have had any type of MS. A convenience sample of eleven individuals (1 male, 10 female; age 51.5 ± 12.6 years) with chronic (4-40 years post-injury/diagnosis) neurological disability were recruited for participation in the study. Participants with SCI had a range of neurological levels of injury (T1-L4) and severity [ASIA Impairment Scale (AIS) A-D], while participants with MS had either Relapsing Remitting MS (RRMS), Secondary Progressive MS (SPMS) or Primary Progressive MS (PPMS). Seven participants were randomly allocated to the intervention group and received the Mad Dog meal plan and recipes as well as the 2-part Mad Dog dietary consultation, while four were allocated to the control group and received the Mad Dog meal plan and recipes only. The randomization, participant allocation and participant enrolment were all performed by the first author of this study (GG). The study was registered as a clinical trial (clinicaltrials.gov identifier: NCT05881122). Informed written consent was obtained from all participants and the study received ethical clearance from the Brock University Research Ethics Board (REB #21-054). Participant characteristics can be seen in Table 1.

Table 1.

Participant Characteristics.

Participant	Sex	Age (years)	Condition	Level of Injury	AIS	MS type	Time since Injury or diagnosis (years)
Intervention Group
1	M	67	MD	—	—	n/a	23
2	F	56	MS	—	—	SPMS	20
3	F	51	MS	—	—	RRMS	9
4	F	39	SCI	T1	A	n/a	23
5	F	57	SCI	T5	B	n/a	40
6	F	52	MS	—	—	RRMS	13
7	F	63	MS	—	—	SPMS	31
Mean±SD		55.0±9.1					22.8±9.6
Control group
8	F	43	MS	—	—	PPMS	17
9	F	63	MS	—	—	SPMS	31
10	F	53	MS	—	—	RRMS	14
11	F	23	SCI	L4	D	n/a	4
Mean±SD		45.5±14.8					16.5±9.7

AIS, ASIA (American Spinal Injury Association) Impairment Scale; MD, Muscular Dystrophy; MS, Multiple Sclerosis; SCI, Spinal Cord Injury; PPMS, primary progressive MS; SPMS, secondary progressive MS; RRMS, relapsing remitting MS

Randomization

Once admitted into the study, participants were randomized (computer-generated) by the primary investigator and stratified by participant gender and age using permuted blocks of two (male/female) and blocks of three (>60 years of age, 40-60 years of age, <40 years of age). Randomization was 2:1 to the Mad Dog consultation group vs the control group (Figure 1).

Figure 1.

CONSORT 2010 Flow Diagram.^13,14

Study Design

Once officially enrolled into the study and randomized into groups, all participants completed a 7-day food log and were then shown the Mad Dog meal plan and recipes which includes a 2-week cycle (repeated over the course of the study) with three meals and two snacks per day, for 5 days of the week (participants were allowed to eat what they liked on the remaining two days; typically weekends). Immediately after seeing the Mad Dog meal plan and recipes, all participants completed the baseline testing which included the completion of questionnaires to determine their perceived task and barrier self-efficacy for adhering to the Mad Dog diet, as well as their self-reported neuropathic pain and depression (see below for details). As soon as possible following baseline testing (within one week), the intervention group was given the two-part Mad Dog dietary consultation, as well as the Mad Dog meal plan and recipes, while the control group only received the Mad Dog meal plan and recipes. To gauge the immediate effects of the Mad Dog consultation, the intervention group completed the questionnaires for task and barrier self-efficacy right after the consultation. To gauge the long term effects of the Mad Dog consultation, both groups completed the 7-day food log and all questionnaires (task and barrier self-efficacy as well as self-reported neuropathic pain and depression) at the 1-month timepoint. This timepoint was chosen as previous studies have shown one month to be a sufficient amount of time to realize changes in both neuropathic pain and depression with an anti-inflammatory diet intervention.^13,14

The Mad Dog Diet

Details regarding the original anti-inflammatory diet studies in our lab have been published in previous reports.^13,24 In brief, the diet eliminated foods that have been shown to be pro-inflammatory (refined sugars, hydrogenated oils and processed foods) or commonly associated with even mild intolerances (cow’s milk). Coffee was also restricted and alcohol consumption was discouraged although two bottles of beer per week were permitted. Participants were given a 1-week meal plan that included 3 meals and 2 snacks per day, and the plan was repeated over the course of the 12-week intervention. Participants were also given a list of foods to eat and avoid so that ingredients could be substituted when desired. In addition, the original anti-inflammatory diet also required participants to consume daily supplements with established anti-inflammatory benefits, such as Omega-3 (Now Ultra omega-3; 500 mg EPA and 250 mg DHA, at a dosage of three per day, Chlorella (Now chlorella; containing 1000 mg, at a dosage of six per day), Antioxidants (CanPrev antioxidant network; 100 mg coenzyme Q10, 200 mg n-acetylcysteine, 150 mg mixed tocopherols, 100 mg DL alpha lipoic acid, 60 mg green tea extract, 5.5 mg zinc and 100 μg selenium, at a dosage of two per day), and Curcumin (AOR Inflanox; 400 mg, at a dosage of three per day). A vegetable-based protein powder (Progressive Vegessential) containing 27 g of protein was taken at a dosage of one scoop each morning.

The Mad Dog diet was very similar to the original anti-inflammatory diet, but with a few important differences that were designed to increase adherence and enhance the anti-inflammatory nature of the diet. As mentioned, the Mad Dog diet was based on a 5-day per week meal plan rather than a 7-day per week meal plan, as occasional cheat days were identified as a facilitator for long term adherence. ¹⁹ Similarly, as the expense of the anti-inflammatory supplements were identified as a barrier to long term adherence, ¹⁹ they were eliminated from the Mad Dog diet, and the micronutrients were replaced as best as possible with whole foods. Lastly, the diet was based on a 2-week meal plan that was repeated over the course of the intervention to provide participants with more variety and the meals were designed by local chefs to enhance palatability and value. Participants were still provided a list of foods to eat and avoid, although lectin-containing foods were eliminated from the Mad Dog diet as a means to increase its anti-inflammatory effects. It is important to note that the primary purpose of the present study was not to test the effectiveness of the Mad Dog diet, but rather to determine if the Mad Dog consultation can increase self-efficacy and adherence to the diet in those with neurological disability.

The Mad Dog Consultation

As mentioned, the Mad Dog consultation was delivered in two parts over consecutive days. Part I entailed an accompanied trip to the participant’s preferred grocery store in order to show the participant where selected foods could be found, how to read nutrition labels so that acceptable substitutions to the Mad Dog ingredients could be made, and how to shop for value when choices are presented. Part II of the consultation occurred in the participant’s home and focussed on meal preparation and kitchen accessibility, as well as a brief overview regarding the negative consequences of chronic inflammation, and the positive effects of adopting an anti-inflammatory diet. Accordingly, the researchers travelled to the participant’s home and prepared two sample dinner meals for the participant in an interactive and instructional format. The researchers also brought selected pieces of accessible cooking equipment (designed for use in those with reduced hand function) which were demonstrated during the meal preparation. Participants were not given the equipment to keep, but they were instructed where to buy the equipment online if they found it beneficial. The accessible equipment included a t-fal brand lightweight pot and pan, a t-fal brand accessible slicer/mandolin, a Bios brand ‘easy-grip’ knife, a Ninja brand buttonless blender, and Rehabilitation Advantage brand wide-handled eating utensils. Questions and discussion were highly encouraged throughout the consultation and written materials were left with the participants allowing them to easily review and reference information that was covered during the meeting. Specifically, participants were given a booklet with 28 compliant recipes, additional snack ideas and shopping tips along with a brochure summarizing the consult. The combined length of the consult was approximately 90-120 minutes. Discussions included an open dialogue regarding the participant’s past experiences with anti-inflammatory eating (if any) and what they believe to be their personal barriers and facilitators.

Lastly, the Mad Dog consultation also included a virtual group for those in the intervention group only, where participants could share and discuss anti-inflammatory recipes (that may complement the recipes in the Mad Dog diet) and engage in social support. Researchers were part of the group to oversee discussion but did not participate.

Outcomes

The primary outcome measures for this study were task and barrier self-efficacy to gauge the participants’ confidence for adhering to the Mad Dog diet as well as their actual adherence to the diet over the ensuing month determined by 7-day food logs. Self-reported depression and neuropathic pain served as secondary outcomes. All outcome measures were obtained online.

Task and barrier self-efficacy were measured via a custom-designed 6-item and 7-item questionnaire, respectively, and all items were scored on a 7-point Likert scale ranging from 1 (not confident at all) to 7 (completely confident). The task self-efficacy questionnaire asked participants to rate their confidence for adhering to the Mad Dog diet for any given duration and degree of compliance (e.g. how confident are you that you can follow the Mad Dog diet for 3 months at 70% adherence?), while the barrier self-efficacy questionnaire asked participants to rate their confidence for overcoming previously identified barriers associated with dietary adherence (e.g. how confident are you that you can adhere to the Mad Dog diet during social events and holidays?) (See Appendix A).

Adherence to the Mad Dog diet was measured through the completion of 7-day food logs. Both groups filled out two food logs, one at baseline and one for the last seven days of the intervention. Participants were advised to be as detailed as possible. Food logs were analyzed for the number of servings the participant ate that were approved on the Mad Dog diet, the number of servings that were not allowed (cheats) and the total servings eaten over the week. Adherence rates were determined by calculating [(servings allowed/total servings) * 100].

Participants were asked to complete the Neuropathic Pain Questionnaire (NPQ) at each of the two testing sessions, as a means of assessing self-reported neuropathic pain. The questionnaire consisted of 32 items pertaining to three unique categories including sensory items, affective items, and sensitivity items. Sensory items were those related to the specific type and severity of pain felt (e.g. degree of burning, stabbing, throbbing), affective items related to how the pain affected the participant in daily life (e.g. how irritating is your usual pain?) and sensitivity items related to how various stimuli may act to increase pain (e.g. increased pain due to heat). Participants were asked to rate their pain numerically on a scale from 0-100 whereby 0 indicated the complete absence of pain and 100 indicated the worst pain imaginable. Scores from each of the three categories were averaged for use in statistical analysis.

Participants completed the Centre for Epidemiological Studies Depression Scale (CES-D) at each of the two testing sessions, as a means of assessing symptoms of depression. The questionnaire consisted of 20 items related to depression, and participants were asked to rate how often they experienced each item over the previous 7-day period. Ratings were based on a 4-point scale including ‘rarely or none of the time’ (less than 1 day), ‘some or a little of the time’ (1-2 days), ‘occasionally or a moderate amount of the time’ (3-4 days) or ‘most or all of the time’ (5-7 days). Points for each item ranged from 0 to 3 depending on frequency, and each item was summed for a total score ranging from 0 to 60 with higher scores indicating the presence of more symptomatology. Although this tool is not recommended for diagnoses by itself, a score of 16 points or greater is considered indicative of clinical depression.

Statistical Analysis

All data was found to be normally distributed using Shapiro-Wilkes tests. To assess whether the Mad Dog consultation had an immediate effect on self-efficacy in the intervention group, t-tests were conducted to compare task and barrier self-efficacy from baseline to immediately post-consult. Effect sizes were reported using Hedge’s g to correct for the relatively small sample size in this study. Hedge’s g is a modification to the more commonly used Cohen’s d and is appropriate to use in sample sizes under 20. ²⁵

To assess whether the Mad Dog consult group experienced greater improvements in long term dietary adherence and self-efficacy, as well as the health outcomes of neuropathic pain and depression compared to the control group, these data were compared via 2-way (group x time) repeated measures analysis of variance (ANOVA) with two factors for time (baseline and 1-month post-intervention). Significant group x time interactions were followed by pairwise comparisons to compare specific means as needed. Pearson r correlational analyses were used to detect potential relationships between variables.

All data was analyzed using SPSS software (version 28.0.1.1) and for all statistical tests a P-value of <.05 was chosen to indicate significance with trends being set at a threshold of P < .10.

Results

There were no dropouts in this study. All participants in both groups completed the data collection in full, without declining to answer any questions. All participants in the intervention group completed both parts of the Mad Dog consultation in full and adhered to the Mad Dog diet as best as possible (see adherence below). There were no adverse effects from either the intervention or the data collection process.

Immediate Effects of Mad Dog Consultation

The results of a two-tailed t-test indicated that the consult had a significant positive effect on barrier self-efficacy directly following the consult (P < .001). There was a small effect size for this relationship (g = .40).

Likewise, the results of a two-tailed t-test indicated that the consult was associated with a significant improvement on task self-efficacy directly following the consult (P = .01) with a medium effect size (g = .65) (Table 2).

Table 2.

The Immediate Effects of the Mad Dog Consultation on Self-efficacy Scores.

Timepoint	Baseline	Post-intervention	P-value	Hedge’s g
Barrier SE scores	36.0±8.5	40.4±8.2	.0007	.40
Task SE scores	30.5±6.4	34.5±6.1	.01	.65

SE = Self-efficacy. Values are Means ± SD.

Long Term Effects of the Mad Dog Consultation

Dietary Adherence

Two-way ANOVA showed a significant group x time interaction for dietary adherence (P = .001). Post hoc analysis showed that the intervention and control groups did not differ in their eating behaviour at baseline (P = .614) but that at the 1-month timepoint the intervention group tended to have significantly greater dietary adherence compared to controls (P = .063). Further, the intervention group showed a significant increase in adherence to the Mad Dog diet from baseline to the 1-month post-consultation timepoint (P < .001) while the control group did not (P = .344) (Table 3).

Table 3.

Long Term Effects of the Mad Dog Consultation on Dietary Adherence and Self-efficacy.

Measure	Control Group		Intervention Group
	Baseline	1-month post	Baseline	1-month post
Adherence (%)	50.3 ± 24.9	56.5 ± 36.2	44.7 ± 11.1	88.4 ± 14.5*
Barrier SE	33.3 ± 8.8	25.5 ± 14.2	36.0 ± 8.5	39.6 ± 6.0
Task SE	22.3 ± 4.8	18.3 ± 7.5	30.5 ± 6.4	32.1 ± 6.8

SE, self-efficacy. Values are Means ± SD. * indicates a significant increase in adherence in the intervention group compared to baseline.

Barrier Self-Efficacy

There was a trend for a group x time interaction for barrier self-efficacy (P = .065) one month after the consultation (Table 3).

Task Self-Efficacy

There was a trend for a group x time interaction for task self-efficacy (P = .10) one month after the consultation (Table 3).

Depression

Two-way ANOVA showed a significant group x time interaction for CES-D scores (P = .038). Post hoc analysis showed no differences between groups at baseline (P = .604) but significant differences between groups were seen at the post-intervention timepoint (P = .036). Further, there was no difference in CES-D scores from baseline to post-testing in the control group, while the intervention group showed a significant decrease in CES-D scores from baseline to post-testing (P = .02). Five participants in the intervention group had CES-D scores of 16 or greater at baseline (indicative of clinical depression), and of these participants, three showed CES-D scores of less than 16 at post-testing (Table 4).

Table 4.

Long Term Effects of the Mad Dog Consultation on Depression and Neuropathic Pain.

Measure	Control Group		Intervention Group
	Baseline	1-month post	Baseline	1-month post
CES-D score	19.8 ± 13.0	22.3 ± 8.2	16.00 ± 10.1	10.1 ± 7.7*†
NPQ sensory score	35.8 ± 19.9	30.63 ± 21.7	23.92 ± 20.4	19.36 ± 19.5
NPQ affective score	61.2 ± 27.0	53.28 ± 32.9	32.44 ± 27.6	25.68 ± 26.2
NPQ sensitivity score	39.6 ± 29.2	39.6 ± 32.2	29.5 ± 28.4	19.7 ± 20.1

CES-D, Centre for Epidemiological Studies-Depression; NPQ, Neuropathic Pain Questionnaire; Values are Means ± SD. * indicates significant decrease in CES-D scores in the intervention group compared to baseline; † indicates significant difference between intervention and control groups at 1-month post-testing.

Neuropathic Pain

Two-way ANOVAs were conducted for each of the three sections of the NPQ, as well as the total composite score. None of the tests returned significant group x time interactions (Table 4).

Correlational Analysis

The Pearson r correlational analyses showed that changes in CES-D scores were significantly negatively correlated with dietary adherence (r = −.61; r² = .37; P = .045), and barrier self-efficacy (r = −.77; r² = .59; P = .009). Additionally, there was a trend towards a significant negative correlation between the changes in adherence and NPQ pain sensitivity scores (r = −.53; r² = .28; P = .095).

Discussion

The main findings of the current study are that the two-part Mad Dog dietary consultation had immediate positive effects on barrier, and task self-efficacy. Furthermore, at 1-month follow-up, this consultation was associated with significantly increased adherence to the Mad Dog anti-inflammatory diet and significantly decreased depression scores in the intervention group compared to controls. Furthermore, correlational analyses showed that greater improvements in dietary adherence were associated with greater decreases in depression scores, and in fact, 37% of the variability in depression was accounted for by the variability in dietary adherence. Although changes in self-efficacy and neuropathic pain one month following the intervention did not reach statistical significance, correlational analyses again showed that those who had the greater increases in dietary adherence tended to have the greater decreases in the sensitivity component of the NPQ.

Improvements in self-efficacy should directly minimize previously identified barriers for adherence to an anti-inflammatory diet. ¹⁹ For example, past participants found cost to be an issue as the associated foods and supplements were expensive. One of the components of the consult was to teach participants how to shop in accordance with the diet while still shopping for value along with removing the need for additional supplements. Similarly, knowledge regarding meal preparation was another issue that was tackled. The consult included the demonstration of two participant-selected meals as well as a run though of the entire diet plan with the participant free to ask any questions. Participants were given strategies towards meal planning and preparation as well as the opportunity to use helpful accessible kitchen equipment. Participants were given options on purchasing accessible equipment and multiple participants expressed interest. Through administering the consult individually with each participant (sometimes with the presence of their families and/or support persons), this study successfully managed to provide a more personalized approach that took the individual, as well as their environmental and socioeconomic factors into consideration, as suggested by Bailey and colleagues. ¹⁹

Self-efficacy has been suggested to be an important factor in dietary behaviour, ²⁶ and the consultation in this study utilized behaviour change techniques to address recognized sources of self-efficacy such as promoting vicarious experiences and persuasion, and removing self-doubt. ²⁷ For example, running through recipes and demonstrating accessible kitchen equipment gave the participants a sense of vicarious experience whereby seeing someone else perform tasks relevant to their goals, increased their confidence that they could successfully perform those tasks as well. Likewise, social support via the Facebook^® group allowed for participant interaction which in turn, increased feelings of vicariousness and encouragement. Guiding the participants through ways to successfully incorporate the diet into their lives and allowing for an open dialogue so that questions and concerns could be addressed allowed for persuasion. Responses to questions would often include gentle encouragement and further clarify any confusion to help remove self-doubt. These behavioural change techniques focussed on self-efficacy and their effects on dietary adherence allowed for feelings of mastery towards the diet. Additionally, self-monitoring has been identified as a source of self-efficacy. ²⁶ This component was also addressed in this study through the use of self-report food logs.

As hypothesized, addressing previously identified barriers and reinforcing identified facilitators ¹⁹ improved participant self-efficacy and adherence to the Mad Dog diet. It is also reasonable, based on past results from our lab^8,13 that the improved adherence to the Mad Dog anti-inflammatory diet was responsible for the improvement in depressive symptoms in our experimental group after only one month. As mentioned, correlational analysis showed a negative relationship between the changes in CES-D scores and changes in adherence, suggesting that those who made the greatest changes in adherence also experienced the greatest decreases in depressive symptoms. Therefore, the current study adds further support for the ability to improve mood after only one month of following an anti-inflammatory diet in populations with neurological disease. In turn, improvements in mood would likely promote ongoing dietary adherence to the diet as previous work from our lab has shown perceived health benefits to be a facilitator. ¹⁹ The results of the current study also showed a significant negative correlation between the changes in barrier self-efficacy and the changes in CES-D scores, suggesting that 59% of the variability in depressive symptoms can be accounted for by the variability in barrier self-efficacy. It is possible that increased confidence in one’s ability to overcome barriers toward dietary adherence can promote a sense of autonomy, functionality and control, the loss of which are common predictors of depression in individuals with MS and SCI.^28,29

The current study showed no effect of the Mad Dog anti-inflammatory diet on neuropathic pain, despite previous research from our lab that has shown an anti-inflammatory diet to have analgesic effects after one month. ¹⁴ This finding is somewhat unexpected as the dietary adherence rates as well as baseline neuropathic pain scores in the intervention groups were very similar when comparing the two studies. As mentioned, it is important to note that the current Mad Dog version of the anti-inflammatory diet has been modified since its original version in an attempt to improve long term adherence. The two versions of the diet were matched for nutrients as best as possible; however, it may be that the current version of the diet may not have a high enough quantity, or the right mix, of certain analgesic nutrients. Furthermore, the current version of the diet only demanded 5 days per week of adherence rather than the original 7 and the current study included individuals with SCI, MD and MS rather than SCI alone. Further research is required to determine if the Mad Dog diet is as effective as the original version of our anti-inflammatory diet on decreasing neuropathic pain.

Regarding the persistence of the effects of the Mad Dog consultation, participants showed immediate benefits in both measures of self-efficacy. However, at the 1-month timepoint there was only a trend for improved task and barrier self-efficacy compared to baseline scores in the intervention group. Our study may have been insufficiently powered to detect the differences between baseline and 1-month post-intervention, or participants may have felt a strong sense of confidence and motivation directly after receiving the consultation that may have slightly diminished once they were further removed from the consultation and attempted to apply it. Beyond further refining the consult based on participant feedback, other modifications could be made to help sustain improvements in self-efficacy such as providing regular ‘booster’ sessions for a predetermined amount of time after the first consultation or short, regular virtual check-in sessions, which were done in previous research from our lab. ¹⁴ The idea of additional booster sessions was also proposed for improving self-efficacy using a single home-based consultation aimed at improving exercise behaviours. ²³ Regarding booster sessions for our purposes, they could be used to answer any questions or concerns that participants may have while adopting the diet in their everyday life, for providing additional encouragement, and for providing the opportunity to introduce additional recipes and accessible equipment. It is also possible that booster sessions could maintain the sense of accountability that participants feel when they are part of a study, that otherwise wanes when their responsibilities are over; a phenomenon that has emerged as a barrier to dietary adherence in previous studies. ¹⁹ Longer term follow-up studies are certainly warranted to determine if the benefits of our consultation persist or not over time, and what factors may help to sustain them.

In addition to booster sessions, the Mad Dog consultation may also be improved with the addition of a condition-matched peer mentor as was used in the study by Latimer-Cheung and colleagues. ²³ Participants in that study indicated that peer involvement during the home-visit was helpful, and that they could relate to the peer more so than someone without shared experiences. A peer mentor would also presumably provide a stronger source of vicarious learning, given their similar experiences. ²⁷

Future Directions

Other than the aforementioned modest sample size and the need for follow-up, this study had limitations that should be noted. First, by choosing to participate in the study, participants demonstrated an interest in actively trying to improve their health and well-being. Therefore, the participants in this study may not be representative of the general neuro atypical population, which much like the general population will contain individuals who will not be as self-motivated about improving their health behaviours. Likewise, the primary recruitment strategy for this study also targeted people who were part of an accessible exercise program, and thus, participation in this program could skew towards those who have a tendency to prioritize their health. In addition, all the data in this study was obtained through self-report measures. These measurement tools not only rely on memory to some degree, but also participants may tend to report more positive health results to conform towards the study’s conjecture or to avoid the embarrassment of reporting less healthy self-perceptions and behaviours, despite all data being anonymous. Regarding the task and barrier self-efficacy tools specifically, these were custom-designed by the research team for this study and as such, these questionnaires have not been previously validated. Further research is certainly warranted to validate self-efficacy tools targeted at the improvement of eating behaviours in those with physical disability. In the meantime, the authors have included the task and barrier self-efficacy tools used for this study in the Appendix and welcome others to use it for comparative purposes in studies involving dietary change in those with physical disability.

Conclusions

The two-part Mad Dog dietary consultation resulted in immediate increases in task and barrier self-efficacy regarding adherence to an anti-inflammatory diet in individuals with neurological disability, and these improvements tended to persist one-month following the intervention. In addition, the consultation resulted in improved dietary adherence and mood measured at one-month post-intervention. Last, improvements in dietary adherence and barrier self-efficacy were both significantly associated with improved mood. Future studies are required to determine if the effects of the consultation last beyond one month and how best to sustain positive changes in self-efficacy, dietary adherence and health outcomes.

ORCID iD

David S. Ditor https://orcid.org/0000-0001-8045-9433

Data Availability Statement

Data generated or analyzed during this study are available from the corresponding author upon reasonable request.