GNL Guides

Build solid foundations,
follow your curiosity,
and learn about tech.

Twelve foundations, six core guides, four key guides, four technology guides (two of which branch into device-specific deep-dives: CGM sensors and AID systems), and two guides for life stages. Score 9 out of 10 and you earn a certificate you can keep. The set grows as new evidence and new devices are published.

See the Learn T1D Map

Five sections, 17 entry tiles, 65 live guide pages beneath them, 36 quizzes that end in a certificate. Read from the live site on 26 July 2026.

Sequentialfollow it in orderClusteran entry page with parts under itSingle pageread it and you are doneQuizends in a quiz and a certificate
You are here
GNL Guides
/gnl-guides/
Section 1
Start here, the foundations
One hub, twelve parts, twelve quizzes
Foundations Sequential
/diabetes/
The only part of the site built to be walked in order. Each part ends in a quiz, so you know the ground is solid before you stand on it.
1What type 1 diabetes is2CGM3Basal insulin4Bolus insulin5Correction insulin6Carbohydrate counting7Three balanced meals8Hypoglycaemia9Hyperglycaemia10Ketones11Fast and slow movers12Measuring success
Finishes by pointing you onward to HbA1c and time in range, in section 3. That is the only hand-off the page makes for you; everything else you choose.
Section 2
Core management
Six tiles, browse in any order
Mealtime insulin Hub quiz
/mealtime-insulin/
High carbohydrate mealsBalanced mealsHigh fat meals
Insulin on board Hub quiz
/insulin-on-board-t1d/
1 Physiology mismatch2 Devices3 How devices calculate4 Two models
Hypoglycaemia, advanced Cluster quiz
/recognising-hypoglycaemia/
1 Recognising2 Treating3 Preventing
Dynamic glucose management Quiz
/dynamic-glucose-management-2/
Opens onto GAMESETMATCH
Exercise Single page Quiz
/exercise/
Activity snacking Single page Quiz
/activity-snacking/
Section 3
Key guides
Three tiles, the long reads
HbA1c and time in range Hub quiz
/hba1c-tir-guide/
1 CGM zones2 Glycator biology3 Find your status4 Personalised target5 The ninety day rule
Partying with T1D Hub quiz
/partying-t1d/
AlcoholStimulantsCannabis and hallucinogens
Overcoming insulin resistance Cluster quiz
/overcoming-insulin-resistance-t1d/
1 Understanding it2 Seven ways to combat it
Section 4
Technology, medicines and the evidence
Five tiles under two headings
Devices and medicines
CGM Hub quiz
/cgm-guide/
Dexcom G7FreeStyle LibreRoche SmartGuideMedtronic Simplera
Each device page carries its own quiz.
Automated insulin delivery Hub quiz
/automated-insulin-delivery-systems-aids/
t:slim X2 Control-IQMiniMed 670G and 780GCamAPS FXOmnipod 5
Each device page carries its own quiz.
GLP-1 and T1D Single page Quiz
/faq-glp1-tld/
Skincare Single page Quiz
/faq-skincare/
Reading the evidence
How to read a research study Hub quiz
/how-to-read-a-research-study/
Seven parts
Section 5
Children and young people
Two tiles by age band
Infants and preschoolers Quiz
/paediatric-t1d-infants-and-preschoolers/
Adolescents, ages 15 to 17 Quiz
/paediatric-t1d-adolescent-ages-15-to-17/

1. Start here, the foundations

You need a score of 9 out of 10 on all twelve module assessments before tackling the more advanced guides. Every other guide assumes you have solid foundations in place.

Start here

Foundations

Everything else on this page assumes these are already in place. Twelve short parts in order, from what type 1 diabetes is, through the highs, the lows and carb counting, to ketones and measuring whether things are going well.

Read the guide →

Foundations first, always. The guides below offer extra insight to those who have solid foundations.

2. Core management

The day-to-day. Mealtimes, insulin on board, dynamic glucose management, more on hypos, and activity and exercise.

Mealtimes

Mealtime Insulin

A high-carb plate, a balanced plate, and a pizza each ask something different of the same dose. Three parts on getting the timing and the shape of the dose to match the meal.

Read the guide →
Active insulin

Insulin on Board

What is still working from the last dose, and why your device’s answer may not match your body’s. Four parts on the models behind the number, the device settings, and the trade-off in a shorter or longer active insulin time.

Read the guide →
Trends and patterns

Dynamic Glucose Management

Some glucose moves fast and some moves slow, and the two need different responses. The GAME, SET and MATCH framework, how it compares with an AID system, and what to look for in your own CGM data.

Read the guide →
Exercise

Exercise

Fast physiology meeting slow insulin. Where the risk actually sits before, during, and after a session, on injections and on an AID system, with an explorer for planning your own.

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After meals

Activity Snacking

Ten minutes of movement after a meal is a lever most people already have and rarely pull. A short read on what post-meal movement does to the curve.

Read the guide →
Hypoglycaemia

Hypoglycaemia, Advanced

Warning signs can fade quietly, and the overnight report is often the only place the pattern shows. On how awareness is measured, what a relative hypo is, and how the picture differs for children.

Read the guide →

3. Key guides

The depth guides worth knowing exist once the day-to-day is settled: measurement, a night out, and insulin resistance.

Measurement

HbA1c and Time in Range

Two people with the same HbA1c can be running very different glucose. Five parts on your CGM zone, your glycator status, and finding a time-in-range target that fits you rather than the default.

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Nights out

Partying with Type 1

Alcohol, stimulants, and psychoactives share two problems in type 1: the dose is uncertain and self-rescue is harder. Written for adults, for the night as it actually goes.

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Mechanism

Insulin Resistance

Type 1 is uniquely exposed to insulin resistance. Part 1 maps the causes, what insulin-sensitive looks like in numbers, and why fat loss can feel like a trap.

Read the guide →

4. Technology, medicines and the evidence

The kit, the medicines, and how to weigh the research for yourself. We only cover what we would use ourselves and give the people we love, and we show our working.

Devices and medicines

CGM sensors

CGM

Five questions decide whether a sensor has been tested properly. Then a deep dive into the ones that clear all five: Dexcom, Libre, Roche SmartGuide and MiniMed.

Read the guide →
AID systems

AID

Every system that clears the evidence bar, and what each algorithm asks of you. No system wins on time in range, so the selector matches your top two.

Read the guide →
Answers

GLP-1 Q&A

Evidence-graded answers on GLP-1 and GIP therapy in type 1: what the trials show, how insulin reduction is approached, and the safety questions worth taking to your team.

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Skin and sites

Skincare

Sensors and infusion sets ask a lot of the same skin. What tends to go wrong, and the five habits that keep sites usable, from where they go on to how the tape comes off.

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Reading the evidence

Critical appraisal

How to Read a Research Study

A headline rarely survives contact with the study behind it. Seven parts on reading a paper for yourself, so you can see what a result does and does not support.

Read the guide →

5. Children and young people with type 1 diabetes

Type 1 changes as a child grows. Guides for the years where the ground shifts fastest.

Parents and carers

Infants and Preschoolers (Under 6)

The dose is small, the child cannot tell you they feel low, and the work is largely yours. On the patterns that show up before school age, and what carers say they need at home.

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Adolescence

Adolescents (15 to 17)

The dip through these years is structural, not a personal failure. On distress, disordered eating, technology refusal, and the parent role shifting from manager to coach.

Read the guide →