Study analysis · Primary care diabetes · 2025
Ramadan fasting could cause dangerous blood sugar swings in diabetics — even if they’re well-controlled.
Muslims with type 2 diabetes who fast during Ramadan are almost twice as likely to have wild blood sugar swings, up or down.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
In simple terms
This study looked at people who fasted during Ramadan and noticed their blood sugar levels changed, but it didn't control for other things like what they ate or how much medicine they took. So we can't say fasting caused the changes—just that they happened together.
What’s the bottom line?
This study looked at Muslim adults with type 2 diabetes who fasted during Ramadan and compared their blood sugar changes to non-Muslim diabetics.
How strong is this study?
The study used real doctor records, which is good, but we don't know how they picked the people or if they accounted for other reasons blood sugar changed. That makes it harder to trust that fasting was the real cause—so we should be careful believing strong claims.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
31 / 100
- Randomizationnot randomized
- Blindingblinding unclear
- Control group+15/15
- Sample sizeno sample size reported
- Follow-up+10/10
100 / 100
77 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
This design cannot establish causation — the findings describe an association, not a cause. This is an observational cohort study using historical data; no randomization was performed, and confounding factors (e.g., diet, medication changes, lifestyle) cannot be ruled out as explanations for observed associations.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding disclosures were reported; the study used retrospective health data without apparent industry involvement.
The study relied on retrospective electronic health records from a state-mandated healthcare provider, with no indication of industry funding, author affiliations with commercial entities, or funder influence on study design or analysis.
Key takeaways
- 01
Muslim diabetics were nearly twice as likely to have big changes in HbA1c (≥0.5%) during Ramadan.
- 02
Those with normal blood sugar before fasting were over twice as likely to have either big drops or big rises in HbA1c.
- 03
Yes — big swings in HbA1c can mean dangerous low or high blood sugar, which is risky for diabetics.
Surprising findings
- Ramadan fasting increased the risk of both significant HbA1c decreases AND increases among those with initially normal blood sugar.Most people assume fasting only lowers blood sugar — but this study found it can cause dangerous highs AND lows, making it a bidirectional risk.
Practical takeaways
Diabetics planning to fast during Ramadan should consult their doctor for personalized glucose monitoring and medication adjustments.
This study used electronic records and didn’t track medication changes, diet, or physical activity — so we don’t know what caused the swings.
low confidenceWhy this study matters
Double the Risk of Blood Sugar Swings
Muslim adults with type 2 diabetes were 1.89 times more likely to experience HbA1c changes of 0.5% or more during Ramadan compared to non-Muslim diabetics. This means their blood sugar control became significantly less stable.
Most people think fasting improves blood sugar — but this shows it can make it dangerously unpredictable, even for those who were previously well-controlled.
Even Well-Controlled Diabetics Are at Risk
Among Muslims with normal HbA1c levels (≤7%), fasting during Ramadan doubled the risk of both dangerous drops (OR=2.62) and dangerous rises (OR=2.85) in HbA1c — meaning their blood sugar could swing wildly in either direction.
It’s counterintuitive: if your diabetes is under control, you’d think fasting is safe. But this study says even then, your blood sugar could crash or spike.
Want the whole report?
Detailed mode opens the full scientific breakdown — every score component, the methodology, conflicts of interest, the evidence analysis behind each claim, and the raw study data.
Overview
What the study found
The study in plain English — the bottom line, every takeaway we extracted, and what to do with them.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
This study looked at Muslim adults with type 2 diabetes who fasted during Ramadan and compared their blood sugar changes to non-Muslim diabetics.
Research results
Muslim diabetics were nearly twice as likely to have big changes in HbA1c (≥0.5%) during Ramadan. Those with normal blood sugar before fasting were over twice as likely to have either big drops or big rises in HbA1c.
What this means - more context
Yes — big swings in HbA1c can mean dangerous low or high blood sugar, which is risky for diabetics.
Assess the impact of Ramadan intermittent fasting on glycemic control in individuals with type 2 diabetes.
Muslim adults with type 2 diabetes had a higher likelihood of experiencing HbA1c changes of ≥0.5% during Ramadan compared to non-Muslims, with increased risks of both significant decreases and increases in HbA1c among those with initially normal levels.
Methods Used
Historical prospective study using electronic health records from a state-mandated provider; analyzed HbA1c and fasting plasma glucose levels 90 days before and 45 days after Ramadan over six years (2011–2016) using mixed-model ANOVA.
Main Finding
Muslim participants had an odds ratio of 1.89 (95% CI: 1.24–2.88) for HbA1c changes ≥0.5% during Ramadan compared to non-Muslims; among those with baseline HbA1c ≤7%, odds ratios were 2.62 (95% CI: 1.15–6.00) for decreases and 2.85 (95% CI: 1.24–6.57) for increases.
Confidence Level
Limited - based on abstract only, full methodology not available
Study Flags
Red Flags
- •Full text not available - methodology details cannot be verified
- •No information on medication changes or dietary adjustments during fasting
- •Confounding factors like socioeconomic status or access to care not addressed
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
Ramadan fasting increased the risk of both significant HbA1c decreases AND increases among those with initially normal blood sugar.
Most people assume fasting only lowers blood sugar — but this study found it can cause dangerous highs AND lows, making it a bidirectional risk.
Practical Takeaways
Diabetics planning to fast during Ramadan should consult their doctor for personalized glucose monitoring and medication adjustments.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Human Cohort Study
Subject
Moderate probability
on the GRADE evidence scale
This study looked at people who fasted during Ramadan and noticed their blood sugar levels changed, but it didn't control for other things like what they ate or how much medicine they took. So we can't say fasting caused the changes—just that they happened together.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Uses real-world electronic health records over multiple years
- Includes objective biomarkers (HbA1c, fasting glucose)
- Uses statistical modeling (mixed-model ANOVA) to analyze longitudinal data
Weaknesses
- Full methodology not available - based on abstract only
- No randomization or control for confounding variables
- Blinding status unknown
Methodology
Evidence Keywords
Statistical Reporting
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
This study looked at Muslim adults with type 2 diabetes who fasted during Ramadan and compared their blood sugar changes to non-Muslim diabetics.
Research results
Muslim diabetics were nearly twice as likely to have big changes in HbA1c (≥0.5%) during Ramadan. Those with normal blood sugar before fasting were over twice as likely to have either big drops or big rises in HbA1c.
What this means - more context
Yes — big swings in HbA1c can mean dangerous low or high blood sugar, which is risky for diabetics.
Assess the impact of Ramadan intermittent fasting on glycemic control in individuals with type 2 diabetes.
Muslim adults with type 2 diabetes had a higher likelihood of experiencing HbA1c changes of ≥0.5% during Ramadan compared to non-Muslims, with increased risks of both significant decreases and increases in HbA1c among those with initially normal levels.
Methods Used
Historical prospective study using electronic health records from a state-mandated provider; analyzed HbA1c and fasting plasma glucose levels 90 days before and 45 days after Ramadan over six years (2011–2016) using mixed-model ANOVA.
Main Finding
Muslim participants had an odds ratio of 1.89 (95% CI: 1.24–2.88) for HbA1c changes ≥0.5% during Ramadan compared to non-Muslims; among those with baseline HbA1c ≤7%, odds ratios were 2.62 (95% CI: 1.15–6.00) for decreases and 2.85 (95% CI: 1.24–6.57) for increases.
Confidence Level
Limited - based on abstract only, full methodology not available
Study Flags
Red Flags
- •Full text not available - methodology details cannot be verified
- •No information on medication changes or dietary adjustments during fasting
- •Confounding factors like socioeconomic status or access to care not addressed
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Surprising Findings
Ramadan fasting increased the risk of both significant HbA1c decreases AND increases among those with initially normal blood sugar.
Most people assume fasting only lowers blood sugar — but this study found it can cause dangerous highs AND lows, making it a bidirectional risk.
Practical Takeaways
Diabetics planning to fast during Ramadan should consult their doctor for personalized glucose monitoring and medication adjustments.
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Human Cohort Study
Subject
Moderate probability
on the GRADE evidence scale
This study looked at people who fasted during Ramadan and noticed their blood sugar levels changed, but it didn't control for other things like what they ate or how much medicine they took. So we can't say fasting caused the changes—just that they happened together.
No conflicts of interest were detected in this study. No score impact.
Strengths
- Uses real-world electronic health records over multiple years
- Includes objective biomarkers (HbA1c, fasting glucose)
- Uses statistical modeling (mixed-model ANOVA) to analyze longitudinal data
Weaknesses
- Full methodology not available - based on abstract only
- No randomization or control for confounding variables
- Blinding status unknown
Methodology
Evidence Keywords
Statistical Reporting
Scoring
How strong is this study?
The study used real doctor records, which is good, but we don't know how they picked the people or if they accounted for other reasons blood sugar changed. That makes it harder to trust that fasting was the real cause—so we should be careful believing strong claims.
0 / 100
- COI disclosureconflicts of interest not disclosed
- Data availabilitydata not shared
- Code availabilitycode not shared
31 / 100
- Randomizationnot randomized
- Blindingblinding unclear
- Control group+15/15
- Sample sizeno sample size reported
- Follow-up+10/10
100 / 100
77 / 100
- P-values+15/15
- Effect size+20/20
- Confidence intervals+15/15
- Pre-registrationnot pre-registered
Each component is scored out of 100 and then capped by the study design — a case series cannot reach the ceiling a randomised trial can, however well it is reported.
Where it sits
RCT reviewsReviews of RCTs (Meta-analyses)
Max 100Randomized TrialsRandomized Trials
Max 90Reviews of Cohort StudiesReviews of Cohort Studies
Max 85Cohort StudiesCohort Studies
Max 72Reviews of Case-Control StudiesReviews of Case-Control Studies
Max 63Case-Control StudiesCase-Control Studies
Max 58Cross-Sectional & Case SeriesCross-Sectional & Case Series
Max 50Expert OpinionExpert Opinion
Max 550 / 100
Probability of being correct
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
This design cannot establish causation — the findings describe an association, not a cause. This is an observational cohort study using historical data; no randomization was performed, and confounding factors (e.g., diet, medication changes, lifestyle) cannot be ruled out as explanations for observed associations.
No Conflicts
No conflicts of interest identified
No conflicts of interest or funding disclosures were reported; the study used retrospective health data without apparent industry involvement.
The study relied on retrospective electronic health records from a state-mandated healthcare provider, with no indication of industry funding, author affiliations with commercial entities, or funder influence on study design or analysis.