Transparency and methodology

How GNL Works

The evidence, the algorithms, GNL Grace, and what all of it can and cannot do. Select a section below.

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What GNL is

GNL — The Glucose Never Lies — is an independent T1D education platform. Everything it produces is built from clinical evidence, tested against real-world data, and communicated in plain language.

This page is a full account of how that works: the evidence foundation, the algorithms behind each educational tool, GNL Grace (GNL’s AI-powered educational advisor), and the real-world validation programme that has tested every major assumption against more than 1.5 million patient-days of data from the Cockpit 1.0/daily dataset (Syno by Syntactiq Dynamics FlexCo, syntactiq.ai).

6 Educational explorers — live on the GNL platform
1.5M+ Patient-days assessed in real-world validation
180+ Peer-reviewed citations in GNL’s evidence base
36+ Expert podcast interviews embedded in the knowledge base

What this page covers

  • Disclaimer and framing — the 20/80 educational philosophy that sits beneath all GNL output
  • GNL evidence base — the guidelines, consensus papers, and original research that underpin every tool
  • GNL Grace — how the AI educational advisor was built, by whom, and what powers it
  • Evidence applied — how guidelines and real-world data were used to validate every algorithm assumption
  • Six explorer walkthroughs — the clinical question each tool answers, its algorithm basis, and what real-world testing found
  • GNL Podcast — how the podcast series layers into and extends the evidence base
  • Contact — where to direct questions about each area

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Disclaimer

The 20% of learning that gets you 80% of the way there.

The final 20% is through guided self-discovery — and a personalised human network who know your diabetes in the way an educational tool never can.

What this means

GNL educational tools give you the 20% of knowledge — with the right mindset and framework — that gets you 80% of the way there. This is not a limitation to apologise for. It is the honest account of what any educational resource, however well-built, can deliver.

Research across complex domains consistently shows that a small fraction of the right knowledge, applied with the right framework, produces the majority of the benefit. In T1D education, this holds true — and GNL’s tools are designed around it.

What the remaining 20% requires

  • Your individual data — your physiological responses to insulin, food, activity, sleep, and stress, which no population-average tool can know
  • Self-discovery over time — the iterative process of observing what works for you specifically and building your own pattern recognition
  • A personalised human network — clinicians, educators, and peers who know you, your history, and your context in ways that cannot be encoded in an algorithm

How GNL is designed around this

Every GNL Explorer, guide, and Grace response is designed to show what the evidence says happens on average for a person with your characteristics — and then explicitly hand you back to your own context and your care team. GNL does not guess where it does not know. It does not extend population findings to individual prescriptions. And it does not pretend that 80% of the way there is the same as arriving.

The full disclaimer

GNL is not a medical device and does not provide personal clinical advice. All outputs are educational and population-average. The explorers model how algorithms and physiological principles behave on average — not how any individual system will behave for you. Any change to your insulin settings, device configuration, or diabetes management must be made in discussion with your diabetes care team.

GNL’s knowledge base is built on three layers: international clinical guidelines, expert consensus papers, and a validated real-world dataset accessed through academic research collaboration. All claims carry an evidence grade.

International guidelines — Grade A

ADA Standards of Care in Diabetes — 2026

The American Diabetes Association’s comprehensive annual standards. GNL’s primary adult guideline for glycaemic targets, pharmacological approaches, technology, and physical activity. Diabetes Care, 2026;49(Suppl 1). Grade A.

ISPAD Clinical Practice Consensus Guidelines — 2024

Insulin and adjunctive treatments (PMID: 39884261), diabetes technologies and insulin delivery (PMID: 39657603), glycaemic targets (PMID: 39701064). Primary source for all explorer algorithm assumptions involving insulin therapy, device use, and glucose targets. Pediatric Diabetes, 2024. Grade A.

ISPAD Clinical Practice Consensus Guidelines — 2022

Including the landmark exercise chapter (Adolfsson et al.) — pre-, during- and post-exercise glucose targets, insulin adjustment strategies, and carbohydrate guidance tables used across GNL’s three exercise-facing explorers. Pediatric Diabetes, 2022;23(7). Grade A.

Key consensus papers

Exercise management in type 1 diabetes

Riddell MC, Gallen IW, Smart CE, et al. Lancet Diabetes and Endocrinology. 2017;5(5):377-390. PMID: 28126459. The foundational consensus for all three GNL exercise explorers — aerobic versus resistance risk, insulin adjustment percentages, post-exercise hypo timing, overnight management. Grade A.

AID systems and exercise — ISPAD/EASD consensus

Moser O, et al. Recommendations for exercise in people with T1D using automated insulin delivery. ISPAD/EASD working group, 2025. Informs AID-specific outputs in Exercise Planning and AID System Explorers. Grade B/C.

T1DEXI — the type 1 diabetes exercise initiative

Multi-site prospective study of real-world exercise patterns and glucose responses in adults with T1D. Granular aerobic versus resistance data underpinning GNL’s intensity modelling. Grade A.

GNL original research

The 20-minute paradigm shift — Pemberton et al. (2023)

Post-meal physical activity and glucose management in type 1 diabetes. Demonstrated that 20 minutes of walking after a meal produces a clinically meaningful glucose reduction at the post-prandial peak. Primary evidence basis for the Activity Explorer’s low-intensity, high-frequency framing. Grade B.

Real-world validation — Cockpit 1.0/daily dataset

Cockpit 1.0/daily dataset — Syno by Syntactiq Dynamics FlexCo (syntactiq.ai)

A large-scale longitudinal real-world T1D dataset — internally referred to at GNL as BFD (Big F***ing Data). The dataset captures continuous CGM readings, insulin delivery events, physical activity, menstrual cycle data, and sleep metrics across a cohort of T1D users over more than a decade. More than 1.5 million patient-days. GNL’s validation programme ran more than 30 structured queries across this dataset between March and April 2026.

Data analysis was performed using Syno by Syntactiq Dynamics FlexCo, including the Cockpit 1.0/daily dataset provided by Syntactiq Dynamics FlexCo (syntactiq.ai). GNL ran more than 30 structured queries testing every major algorithm assumption across all six educational explorers. Grade B (real-world dataset, validated research cohort).

Published research using the Diabetes Cockpit

The following peer-reviewed conference abstracts have used this dataset. Two involve GNL’s own Scientific Advisers.

EASD 2025 + ÖDG 2025 — Exercise and CGM metrics in T1D

Schierbauer J, Sanfilippo D, Sourij H, Moser O, et al. “Acute Exercise Effects on CGM Metrics in T1D.” EASD Annual Meeting 2025 / ÖDG 2025. University of Bayreuth and Medical University of Graz. Prof Othmar Moser is a GNL Scientific Adviser.

EASD 2025 — Long-term exercise and glycaemia in T1D

Moser O, Schierbauer J, Sanfilippo D, Sourij H, et al. “Long-Term Exercise & Glycemia in T1D.” EASD Annual Meeting 2025. University of Bayreuth and Medical University of Graz. Prof Othmar Moser is a GNL Scientific Adviser.

ATTD 2025 — Sleep duration and glycaemic outcomes in AID users

Cooper A, Debong F, Schuster T, Braune K, Tauschmann M. “Population-based study on how sleep duration impacts TIR and TITR in users of automated insulin delivery systems.” ATTD 2025, Amsterdam. Charité Berlin / Medical University of Vienna.

ATTD 2026 (Barcelona) — Glycaemic variability in T1D

Carr A, Munoz Mendoza A, Senior E, et al. “How glycemic variability percentage reveals hidden complexities in glycemic control.” ATTD 2026, Barcelona. University of Alberta. March 2026. Journal publications from this dataset series are in preparation.

Dataset: Cockpit 1.0/daily dataset, Syno by Syntactiq Dynamics FlexCo (syntactiq.ai). Contact: contact@syntactiq.ai.

GNL Grace is the world’s first T1D educational AI advisor built on a curated, evidence-graded clinical knowledge base. Here is the full account of how it was built, what powers it, and who built it.

The team

Knowledge base and clinical content

John Pemberton

Founder and Director, GNL. Diabetes specialist, 20+ years clinical and educator experience. Responsible for all clinical content, evidence grading, and the curated knowledge base that Grace is built on.

Technical architecture and API

Phillip Hayes

Technical Director, GNL. Built the Grace API endpoint (/api/grace/query) on the GNL Laravel platform. Handles all server-side infrastructure, API delivery, and integration architecture.

What powers Grace

Grace is powered by Claude by Anthropic — one of the most capable large language models available. Claude provides the natural language understanding that allows Grace to interpret any T1D question and generate a coherent, evidence-grounded response. The value of this approach is not the AI itself — it is the combination of a state-of-the-art language model with GNL’s curated clinical knowledge base. Neither element works without the other.

The curated knowledge base — GNL’s intellectual property

GNL Grace is grounded in a structured clinical knowledge base built and maintained by John Pemberton. This is not a general-purpose AI trained on the internet — it is a purposefully curated evidence library covering every topic in T1D clinical management, with every claim graded for evidence strength and every source verified. The knowledge base represents hundreds of hours of evidence synthesis, structured to allow Grace to retrieve and cite specific claims rather than summarise or hallucinate.

The language model generates responses. GNL’s curated knowledge base determines what those responses are grounded in. The clinical framing — what Grace can say, how it is qualified, and when it refers users back to their care team — is built into the knowledge base itself, not left to the AI to decide.

How a Grace query works

  • 1
    Question received — via the GNL website widget or the authenticated API endpoint for partners.
  • 2
    Knowledge base searched — Grace searches GNL’s curated clinical evidence across all topic domains. The search is semantic — it finds relevant content even when the exact words do not match the question.
  • 3
    Evidence-graded response constructed — retrieved content is used to build a response that cites the evidence grade for every claim (A/B/C/D). Where evidence is absent or weak, Grace says so explicitly.
  • 4
    Signposting — where a GNL Explorer, guide, or podcast episode addresses the question in depth, Grace points to it. Where the question requires individual clinical judgment, Grace says so and refers the user to their care team.
  • 5
    Disclaimer applied — every response carries the population-average educational framing. Grace never presents an output as individual clinical advice.

What Grace can and cannot do

Grace can

  • Answer any T1D question at population-average level
  • Grade and cite every claim
  • Explain the mechanism behind a glucose pattern
  • Point to the right GNL Explorer, guide, or podcast episode
  • Review a manuscript paragraph for clinical accuracy
  • Summarise key evidence on any topic in the knowledge base
  • Grow continuously as new evidence is added

Grace cannot

  • Tell you what dose to take, adjust, or omit
  • Give advice specific to your individual history or biology
  • Connect to your CGM or insulin pump
  • Replace a consultation with a clinical specialist
  • Account for context only you and your care team can weigh
  • Make the final 20% of the clinical judgment — that belongs to you

API access

Grace is available via authenticated API for clinical and commercial partners who want to embed the best T1D educational advisor in their platforms. The full knowledge base, clinical framing, and evidence grading are all delivered at API level — no degraded copies, no stripped disclaimers. Enquiries: john@theglucoseneverlies.com.

GNL ran a systematic real-world validation programme across all six explorers, testing every algorithm assumption against a validated longitudinal T1D dataset. Here is how the process worked and what it found.

The validation process — five stages

  • 1
    Algorithm design from published evidence — every assumption documented with source citation and evidence grade. Minimum Grade C to enter production. Grade A/B required for any numerical output.
  • 2
    20+ years educator experience as context — clinical evidence sets the numbers. Educator experience determines which questions matter most in practice and how outputs should be communicated to avoid common misapplications.
  • 3
    Real-world validation — 30+ structured queries — every major assumption tested against more than 1.5 million patient-days (Cockpit 1.0/daily dataset, Syno by Syntactiq Dynamics FlexCo, syntactiq.ai). Where assumptions are confirmed, they are retained. Where challenged, the algorithm or framing is updated. Where intraday data is needed, the limitation is documented explicitly.
  • 4
    Piloting with GNL subscribers — structured usability and comprehension testing with an engaged T1D community before broader release. Framing revised where outputs are consistently misunderstood.
  • 5
    Continuous iteration — scholar alert pipeline tracks new publications daily. Algorithm assumptions reviewed as evidence evolves. Every change logged in the GNL Compliance Dossier.

Eight counter-intuitive findings — Via Negativa

These are the findings where real-world data contradicted what guidelines and clinical intuition predict. Each has resulted in an algorithm update or reframing.

Finding 1 — Step count

TIR plateaus at 4,000-5,000 steps per day. Moving from 5k to 10k steps adds essentially no additional TIR benefit (71.6% vs 71.7%). The 10,000-step goal, as a glucose target, is not supported by real-world data. GNL activity threshold recalibrated to 4-5k. 667 users, 373,737 days.

Finding 2 — Exercise and carbohydrates

Real-world users reduce insulin 9.2% on exercise days (p<0.001). Carbohydrate intake on exercise vs rest days: 145.2g vs 146.1g — a non-significant difference. Two independent analyses agree: insulin reduction is the dominant mechanism, not carb addition. This contradicts the assumption all exercise carb calculators are built on. 104,760 days with carb logging; confirmed in 247,585-day supplementary study.

Finding 3 — TIR and hypoglycaemia

Higher TIR users have more hypoglycaemia, not less. Pearson r = +0.163 (p<0.001). High-TIR users average 3.19% TBR — above the international 3% threshold. Chasing TIR without attending to the TBR cost is a real clinical pattern, now real-world validated. 621 users.

Finding 4 — Severe hypo and same-day TIR

Severe hypo days (>4% TBR) show higher same-day TIR than minimal hypo days — 72.5% vs 68.3%. Over-treatment pushes glucose high after the low, inflating same-day TIR. The real cost is the next day: TBR 6.0% vs 1.3%. Validates the 15g rule and adds a new clinical signal: the day after a severe hypo is high-risk. 247,585 days.

Finding 5 — Female pen users and exercise

Female MDI users with high exercise: 60.2% TIR vs 63.8% low exercise — exercise associated with worse outcomes in this group. TBR: 4.3% vs 2.2% — nearly double. This is the highest-risk combination in the entire dataset. Every GNL exercise-facing output is being gender-differentiated as a result. 694 users; flagged to Scientific Advisers for clinical review.

Finding 6 — High glucose variability

High CV users (>36%) already exercise 14% more and bolus 17.5% more frequently than low CV users — yet their TIR is 17.1pp lower with 3.43x hypo risk. The predictors are sleep inconsistency and poor carb logging, not exercise or bolus frequency. High CV is a structural challenge, not a motivational one. 710 users.

Finding 7 — Sleep regularity

Sleep regularity is the #1 TIR predictor for adults aged 31-40 (13.3pp difference, r=-0.292, p=0.024) — but has essentially no effect on 18-30 adults (r=0.029, p=0.89). The population-level 10.8pp finding masks complete age stratification. GNL does not apply sleep messaging universally. Four independent analyses; 233-611 users depending on analysis.

Finding 8 — Sleep versus exercise

Adding exercise to a regular sleep schedule adds only 0.9pp TIR. Moving from irregular to regular sleep in low-exercise users adds 6+ percentage points. Sleep regularity dominates. The Sleep Explorer — GNL’s next product build — is now justified by five independent analyses. Bands validated: <1h SD = 80.9% TIR, 1-2h = 73.4%, >2h = 63.4%.

Explorer 1 of 6

Activity and Exercise Explorer

The clinical question this tool answers: what is exercise actually doing to my glucose, and how can I plan around it safely?

Inputs

  • Current glucose and CGM trend direction
  • Estimated insulin on board
  • Exercise type — aerobic, resistance, mixed, or HIIT
  • Planned duration
  • Device type (MDI or pump/AID)

Outputs

  • Estimated glucose direction during exercise
  • Risk classification (low / moderate / high)
  • Contextual guidance on glucose targets and adjustment strategy
  • Post-exercise risk framing

Algorithm basis

12Audited decision points
A-BRCT and registry evidence for core mechanisms
C-DSpecific numeric parameters — calibrated, not guessed

The algorithm uses a dose-dependent kinetic model to estimate active insulin on board, then combines this with current glucose, CGM trend direction, and exercise type to produce a risk classification and directional glucose estimate. Aerobic exercise carries the highest per-unit glucose drop rate; resistance and anaerobic exercise carry a lower rate due to counter-regulatory catecholamine release. All insulin calculations are weight-normalised (U/kg) and all computations run server-side — no algorithm code is exposed in any browser-facing file.

Key sources: Riddell et al. 2017 (Lancet Diabetes Endocrinol, PMID: 28126459); ISPAD 2022 exercise chapter (Adolfsson et al.); T1DEXI study (Bergford et al. 2023); Moser/EASD 2025 AID consensus; Heise et al. 2017 (rapid-acting insulin pharmacokinetics); Pemberton and Uday 2026 synthesis.

What real-world validation found

Confirmed — aerobic hypo risk and intensity dose-response

Clear dose-response from low to high exercise intensity validated. Very high intensity (>600 kcal active energy): TIR declines, TBR rises progressively to 3.9% above 1,000 kcal. The inverted-U pattern is real. Resistance training carries 0.7pp less TBR than aerobic across matched sessions.

Recalibrated — step count plateau

Plateau occurs at 4,000-5,000 steps, not 10,000. Activity band labels updated. “More steps, better outcomes” messaging capped at 4-5k.

Gap confirmed — gender-specific outputs

Female pen users with high exercise: worse TIR (60.2% vs 63.8%) and nearly double TBR (4.3% vs 2.2%). Gender-differentiated outputs in development.

Explorer 2 of 6

Exercise IOB Calculator

The clinical question: how much insulin is still active, and what does that mean for my safety going into exercise?

Inputs

  • Time since last bolus and dose given
  • Body weight
  • Current glucose and trend
  • Exercise type and planned duration

Outputs

  • Estimated active insulin load — visual risk band
  • Carbohydrate range for pre-exercise coverage (MDI users)
  • Insulin reduction guidance (pump/AID users)
  • Contextual caution based on glucose trend and IOB level

Algorithm basis

11Audited decision points
AISPAD weight-normalised carb framework
8IOB risk bands — V.Low to E.High

The calculator uses a unified sigmoidal pharmacokinetic model of rapid-acting insulin decay to estimate the fraction of each bolus still active at the point of exercise. Dose-dependent kinetics are modelled — larger subcutaneous depots absorb more slowly, producing longer activity tails. The result is an 8-tier risk band (V.Low to E.High) based on estimated active insulin per kilogram of body weight. Carbohydrate recommendations use the ISPAD 2022 weight-normalised framework, scaled by exercise type, glucose band, and IOB exposure. All computations run server-side.

Key sources: Heise et al. 2017 (RCT pharmacokinetic data); Plank et al. 2005; ISPAD 2022 carbohydrate tables (Adolfsson et al.); Riddell et al. 2017; T1DEXI registry (Bergford et al. 2023); Pemberton and Uday 2026.

What real-world validation found

Major reframing — dominant mechanism is insulin reduction, not carb addition

Real-world users reduce insulin 9.2% on exercise days (p<0.001). Carbohydrate intake is unchanged. Two independent analyses agree. The calculator’s primary outputs are being reframed to lead with insulin reduction, with carbohydrate ranges retained as secondary guidance for MDI users who cannot reduce insulin during a session.

Highest-priority pending validation — IOB decay model

The pharmacokinetic decay model underpins every carbohydrate and insulin estimate in every exercise explorer. Its real-world accuracy requires intraday (hourly) CGM data to validate. Daily aggregate data cannot test this. Intraday data access is in progress — until it arrives, the model is the best available published basis, honestly framed.

Explorer 3 of 6

AID System Explorer

The clinical question: I am considering or starting an AID system — what can I realistically expect?

Inputs

  • Current TIR and eA1c
  • Current therapy type (MDI, standard pump, AID)
  • Bolus engagement level
  • Primary management challenge

Outputs

  • Expected AID benefit range with confidence framing
  • Areas of greatest confirmed real-world advantage
  • Where individual engagement still matters
  • Honest statement of what AID cannot do

Algorithm basis

14Audited decision points
228k+Registry users across the four system datasets
3-stepConfiguration framework (Pemberton and Uday 2026)

The explorer incorporates the Pemberton and Uday 2026 three-step AID configuration framework — target, primary lever, basal-bolus split — applied across all four systems. It uses published registry data (Choudhary 780G 101,629 users; Forlenza Omnipod 5 69,902; Messer Control-IQ 20,764; Boughton CamAPS FX 35,714) to model realistic outcomes by configuration tier. The central clinical insight: within-system configuration differences exceed between-system differences. Fewer than 10% of AID users are on optimal settings. All computations run server-side. The responsiveness mapping and system-specific behaviour modelling are proprietary.

Key sources: Choudhary et al. 2024; Messer et al. 2023; Forlenza et al. 2024; Boughton et al. 2026; Bassi et al. 2025; Pemberton and Uday 2026; Biester et al. 2023 (paediatric DPV registry 25,718 young people); ISPAD 2024.

What real-world validation found

Confirmed — direction and overnight benefit

Real-world AID vs MDI: 6.2pp TIR advantage (76.4% vs 70.2%, p<0.001, 839 users, 409,056 days). Below the +10-30pp clinical trial range — selection bias and population differences account for much of the gap. Overnight multi-day cycle-breaking confirmed as the strongest validated benefit: TBR autocorrelation breaks the cycle of recurrent overnight lows more effectively than MDI.

Confirmed — engagement narrows the gap

At high bolus frequency: AID advantage narrows to 2.0pp over MDI. Highly engaged MDI users substantially close the real-world gap. This is now explicit in the explorer’s framing.

Explorer 4 of 6

Hypo and Hyper Explorer

The clinical question: my glucose is going low or high — what is actually happening, and how do I think about the pattern?

Inputs

  • Current glucose level
  • CGM trend and recent pattern
  • Insulin on board and bolus timing
  • Device type and daily insulin dose

Outputs

  • Glucose classification with mechanism explanation
  • Estimated insulin sensitivity factor (TDD-based)
  • Hypo treatment pathway — 15g rule with over-correction warning
  • Next-day risk flag after severe hypo

Algorithm basis

3Tabs — treatment, exercise prevention, high glucose
5-tierGlucose classification framework
A-CISPAD/ADA consensus for treatment thresholds

Three tabs, three clinical contexts. Tab 1 uses a weight-adjusted carbohydrate treatment model grounded in the ISPAD/ADA 15-15 rule — with an explicit over-correction warning driven by the next-day TBR finding from real-world validation. Tab 2 uses the triangular insulin activity model (distinct from the remaining-fraction model in the exercise tools) to estimate current insulin effect intensity before exercise. Tab 3 maps glucose level, duration, and ketone status through a structured educational framework. The ISF correction factor tool uses a TDD-based formula validated as directionally accurate against 1.5M patient-days. All computations run server-side.

Key sources: ISPAD 2022/2024 glucose thresholds; ADA 2026 Standards of Care; Heise et al. 2017 (pharmacokinetics); Pemberton and Uday 2026; 15g hypoglycaemia treatment consensus.

What real-world validation found

Confirmed — ISF formula directionally valid

TDD-TIR inverse relationship confirmed. Low TDD (<20u): 79.0% TIR. Very high TDD (>60u): 66.7% TIR with greater variability. Formula confirmed as directional estimate — individual responses vary significantly. Context note added.

Confirmed — over-correction consequence

Severe hypo days drive next-day TBR to 6.0% vs 1.3% minimal hypo days. Treat once, wait 15 minutes, do not over-treat. Monitor closely the following day. This is now explicit in the output framing.

Confirmed — optimal bolus frequency zone (non-AID)

4-6 boluses per day achieves the best TBR (2.5%) with good TIR. Very high frequency (>6) improves TIR but raises TBR and total insulin. AID exception confirmed: high correction frequency has negligible extra hypo risk in AID users (r=-0.012).

Explorer 5 of 6

Exercise Planning Explorer

The clinical question: I am planning a session — what should I think about before, during, and after?

Inputs

  • Exercise type and planned duration
  • Pre-exercise glucose and trend
  • Device type (MDI or pump/AID)
  • Time of day and IOB estimate

Outputs

  • Pre-exercise glucose target range by device type
  • Recommended bolus adjustment percentage
  • During-session carbohydrate guidance
  • Overnight management framing (MDI and AID)

Algorithm basis

10Audited decision points
6Therapy regimens — MDI, pump, and 4 AID systems
4-phaseBefore, during, after, overnight

A four-phase exercise management framework structured around device type. Supports MDI, standard pump, and all four UK AID systems with system-specific guidance. Pre-exercise carbohydrate tables use the same ISPAD 2022 weight-normalised framework as the IOB Calculator but apply a different formula — IOB is used as an interpolation fraction (capped at a clinically calibrated threshold) with a 60 kg body weight cap to prevent excessive recommendations. AID users receive a 25% universal bolus reduction (vs 25-75% for MDI/pump, scaled by duration and exercise type). Overnight phase explicitly separates AID automode guidance from MDI insulin reduction. All computations run server-side.

Key sources: Riddell et al. 2017; Adolfsson et al. ISPAD 2022; Moser et al. EASD/ISPAD 2025; Campbell et al. 2015 (0.4 g/kg bedtime carbohydrate RCT); Rabasa-Lhoret et al. 2001 (aerobic dose reduction RCT); Pemberton and Uday 2026.

What real-world validation found

Confirmed — device-specific exercise risk

MDI users at high exercise intensity: TBR 3.56% vs pump users 2.64%. The 0.92pp difference is clinically meaningful at this end of the intensity range. Exercise Planning Explorer outputs now apply a more conservative insulin reduction target for MDI users at high intensity.

Gap confirmed — menstrual cycle phase unmodelled

Confirmed by two independent analyses: follicular phase TIR 63.3% (below 70% target); ovulatory phase highest hypo risk; menstrual phase best TIR. A 6.2pp TIR swing across the cycle is now documented. Near-term: language additions. Longer-term: optional cycle phase input.

Explorer 6 of 6

Alcohol and T1D Explorer

The clinical question: what does alcohol actually do to glucose management, and how do I think about the overnight risk?

Inputs

  • Drinking pattern (units, timing, food)
  • Device type (MDI or AID)
  • Typical overnight glucose pattern
  • Physical activity on drinking day

Outputs

  • Overnight hypo risk framing — 6-24h delayed window
  • AID limitation statement — reactive, not proactive
  • Practical overnight management options
  • Next-day monitoring guidance

Algorithm basis

10+Specialist references (Dossier Appendix B)
6-24hDelayed hypo risk window modelled
B-CEvidence grade — mechanism well established

Built around the hepatic gluconeogenesis inhibition mechanism — alcohol blocks the liver’s ability to release stored glucose in response to falling blood sugar, shifting the overnight hypo risk window to 6-24 hours post-drinking. The algorithm models drinking pattern, food intake, device type, and activity level to produce a risk framing with practical overnight management options. AID systems are explicitly framed as reactive, not proactive: they can respond to falling glucose via automated suspension, but they cannot anticipate the metabolic effect of alcohol. For AID users, a 90-minute pre-activation window is modelled, consistent with published AID guidance (2025). All computations run server-side (client-side only until Laravel endpoint is built).

Key sources: Hepatic gluconeogenesis inhibition literature; ADA Standards of Care; ISPAD; Moser et al. EASD/ISPAD 2025; plus 10 specialist references in GNL Compliance Dossier Appendix B.

What real-world validation found

Confirmed via proxy — overnight risk is real

High-activity days (used as alcohol proxy via metabolic mechanism overlap) followed by TBR >5% next day: 21.6% vs 15.6% low-activity days — 38% relative increase (p<0.001, 881 users, 272,837 days). Direction of overnight risk confirmed. AID reactive-not-proactive framing confirmed. Specific timing window (peak at 6-8h vs 10-12h) requires intraday data to validate precisely.

The GNL podcast is not a content product that sits alongside the evidence base. It is a direct input into it. Every episode adds verified clinical evidence to GNL’s curated knowledge base, and Grace can point to specific conversations when they represent the deepest available discussion of a topic.

36+ Episodes with leading T1D clinicians and researchers
100% Expert interviews cross-referenced in GNL’s knowledge base by clinical topic

How the podcast layers into the evidence base

  • 1
    Each episode involves a leading T1D clinician or researcher — including Professor Othmar Moser (Scientific Adviser, GNL), Professor Dessi Zaharieva (Scientific Adviser, GNL), and a growing roster of international diabetes specialists.
  • 2
    Episode content is reviewed for clinical evidence — key claims are checked against published literature, graded, and where new or distinct from existing evidence, added to GNL’s curated knowledge base as a source summary.
  • 3
    Cross-referenced by clinical topic — Grace can identify the specific episode that provides the most useful in-depth discussion on any topic covered by the podcast library, and direct users to it by name.
  • 4
    The CGM series — a structured systematic evidence series applied to CGM device discussion, with study design scoring methodology applied to each device. Grace uses this series to inform CGM selection responses — pointing to the top three clinical decision factors grounded in the evidence.

Produced by

The GNL Podcast is hosted by John Pemberton and produced by Anjanee Kohli, Director of Creativity. Podcast enquiries and guest proposals: anj@theglucoseneverlies.com

Different questions go to different people. Here is where to direct enquiries depending on the area.

GNL Grace and Explorers

GNL Grace · Educational Explorers · Evidence base · API access
John Pemberton
Founder and Director, GNL
john@theglucoseneverlies.com

Questions about how Grace works, the evidence behind any explorer, partnership and API access enquiries, and anything related to the GNL educational platform.

GNL Podcast

Podcast · Guest proposals · Production · Episode enquiries
Anjanee Kohli
Director of Creativity, GNL
anj@theglucoseneverlies.com

Guest proposals, production queries, episode feedback, and all podcast-related enquiries.

Research and clinical partnerships

Research collaboration · Clinical partnerships · Via Negativa consultancy
John Pemberton

Manufacturer partnerships, academic research collaboration, clinical platform integration, and Via Negativa educational consultancy enquiries.