Cross-sectional studyindependent cross-checkfull text checked I-EGG-12 in-depth review
Which foods do people blame for bad dreams?
Dreams of the Rarebit Fiend: food and diet as instigators of bizarre and disturbing dreams.
Overview
Nielsen T, Powell RA. Front Psychol 2015 · PMID 25741294 · DOI 10.3389/fpsyg.2015.00047
About one in six students thought food affected their dreams, mostly dairy.
Does the study support the specific claim? No · Methodological quality: low
Plain-language summary
Study explained simply
- What did the researchers want to find out?
How common is perceived food-dependent dreaming, and which foods are blamed?
- How was the study done?
Questionnaire survey of students
- How many people, animals or samples were studied?
396 students; Students
- What was actually found?
17.8% (68/382) thought food or late eating affected their dreams. Among the few who named foods (32 and 26 people), dairy was blamed most (44% for disturbing, 39% for bizarre dreams); sweets, spicy and starchy foods and meat followed; eggs and chicken were not mentioned.
- How large was the observed effect?
Associations
- What do the results mean in everyday life?
Bad dreams relate more to poor sleep and eating habits.
- What are the study's limitations?
Psychology students given course credit; self-reported beliefs; only about 30 people named foods; many untested-for-chance comparisons
- What does it say about Elawady's specific claim?
Does not support egg/chicken claims.
- Do the results apply to Germany and Europe?
Moderate.
- What can explicitly not be concluded from this study?
Cannot show that any food causes bad dreams, and says nothing about snoring, sinusitis or headaches.
Scientific in-depth review
1. Full reference
- Authors
- Nielsen T, Powell RA
- Journal
- Front Psychol
- Year
- 2015
- Identifier
- PMID 25741294 DOI 10.3389/fpsyg.2015.00047
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
Funding: Natural Sciences and Engineering Research Council of Canada (Grant #312277) and Canadian Institutes of Health Research (Grant #MOP-115125). Authors declare no commercial or financial conflicts of interest.
2. Research question
How common is perceived food-dependent dreaming, and which foods are blamed?
3. Study design and population
- Study design
- Cross-sectional study – Cross-sectional online questionnaire survey (part of a larger survey) of first-year psychology undergraduates
- Population
Undergraduate students in first-year psychology courses at a Canadian university, receiving partial course credit; 130 males (mean age 21.6), 264 females (mean age 21.4), 2 unspecified
- Country
Canada
- Period
Not stated
- Sample size
396 respondents (correlational analyses); 382 for group comparisons (14 missing a food-dreaming item); foods named by 32 (disturbing dreams) and 26 (bizarre dreams) respondents
- Inclusion and exclusion criteria
Students enrolled in first-year psychology courses who completed the questionnaires; no clinical exclusions reported
4. Methods and endpoints
- Exposure / intervention
Self-reported perceived food-dependent dreaming (in-house yes/no and open-ended items); diet quality, eating behaviour (TFEQ-18R, Intuitive Eating Scale), coffee intake, sleep quality (Sleep Questionnaire)
- Comparator
FDD+ vs FDD- respondents; correlations across all respondents
- Endpoints
Prevalence of perceived food-dependent dreaming; foods blamed; disturbing-dreams and vivid-dreams factor scores (in-house 7-item questionnaire, past 2 weeks)
- Statistical methods
Chi-square, binomial tests against equal expected proportions (1/7) of food types, MANCOVA with age as covariate, Pearson/partial correlations; many correlations, no formal multiplicity correction (bold at p<0.01)
5. Actual results
- Results
68/382 (17.8%) perceived food-dependent dreaming (specific foods 11.5%; eating late 9.5%); food causing disturbing dreams 8.9%, bizarre dreams 7.6%; no sex difference. Of those naming foods, dairy was most often blamed for disturbing (14/32, 43.8%; binomial p<0.0001) and bizarre dreams (10/26, 38.5%; p=0.0004); sweets 31% for bizarre dreams (p=0.025); spicy 19%, starchy 16% and meat 13% for disturbing dreams. Eggs and chicken/poultry are not mentioned anywhere in the text. FDD+ respondents were 2.5 years older and reported more disturbed sleep, more disturbing dreams, more coffee and lower intuitive-eating scores. Disturbing dreams correlated with poorer sleep, binge eating, uncontrolled and emotional eating, but not with diet quality.
- Absolute risks
not applicable
- Authors' conclusion
A substantial minority perceive that food makes dreams bizarre or disturbing; dairy most often blamed. Four non-exclusive explanations are proposed (direct food effects, food-induced distress such as lactose intolerance, folklore, misattribution); findings are preliminary and need experimental testing.
6. Strengths
- Validated eating and sleep scales alongside in-house items
- Open-ended food reports coded into categories
- Authors explicitly consider folklore and misattribution
7. Weaknesses
- Convenience sample of young psychology students receiving course credit
- Self-reported, retrospective perceptions; in-house unvalidated dream and food items
- Very few respondents named foods (32 and 26), so food-category percentages are imprecise
- Cross-sectional; no causal inference
- Many correlations without multiplicity correction
- No outcome on snoring, sinusitis or headache; eggs/chicken not reported as a category
8. Risk of bias
- Orienting tool
- No standard tool fits (descriptive cross-sectional perception survey); structured validity judgement
- Type of assessment
- structured assessment based on the full text by a single reviewer (no formal double review)
- Full formal assessment
- no
- Overall risk of bias
- high
- Rationale
Single-reviewer structured judgement based on the full text; not a formal assessment (would need two independent reviewers and a protocol). The study measures beliefs, not food effects.
| Domain | Judgement | Rationale |
|---|---|---|
| Selection / representativeness | high | Course-credit convenience sample of first-year psychology students at one Canadian university. |
| Exposure and outcome measurement | high | Perceptions and dreams self-reported retrospectively with in-house items; recall and attribution bias (folklore) acknowledged by authors. |
| Confounding | high | Group comparisons adjusted only for age; associations with psychopathology-related variables may explain perceptions. |
| Missing data | low | 14 of 396 lacked one item; Ns 357-396 for correlations. |
| Selective reporting / multiple testing | some concerns | Numerous correlations and MANCOVAs without correction; exploratory open-ended coding. |
Full-text review (25 October 2026): Added sample details (382 analysed; only 32/26 respondents named foods), exact food-category percentages, funding (NSERC, CIHR), confirmed eggs/chicken not mentioned and no snoring/sinusitis/headache outcomes; directness downgraded to very_indirect; structured validity domains (overall unchanged: high).
9. Assessment of the statistical interpretation
Descriptive.
10. Relevance to the specific claim
11. Independent contrary findings
Not applicable.
12. Transferability to Germany and Europe
Moderate.
13. Overall methodological judgement
Exploratory survey of beliefs: about 1 in 6 students think food affects their dreams, mostly dairy, sweets, spicy or starchy foods and meat; eggs and chicken are not named. It does not test whether any food causes nightmares and does not address snoring, sinusitis or headaches.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | low |
| Risk of bias | high |
| Precision of results | low |
| Directness | very indirect |
| Reproducibility | partly replicated |
| Consistency with the overall evidence | consistent |
| Regional transferability | moderate |
| Adequacy of the interpretation (by the archive) | not applicable |
14. Open questions
Controlled food-challenge studies of dreaming; whether egg or chicken intake is ever perceived as a trigger in other populations.
15. Linked fact checks
- Eating eggs causes snoring, sinusitis and nightmares in (practically) everyone who eats them, and stopping eggs and chicken relieves headaches. – Studies contradicting or limiting the claim
- Eating chicken causes nightmares, panic attacks, hallucinations and psychological harm in children and adults; panic attacks became widespread in the last 20 years because of mass chicken production. – Studies contradicting or limiting the claim