Guides

GNL Guides

All education and self-discovery guides on The Glucose Never Lies. Start with Foundations, then explore the areas most relevant to your life with type 1 diabetes.

How to use the guides

Foundations are the required starting point. These guides lock in safety, core principles, and baseline competence. Everything else on this site assumes this knowledge.

Start with the Foundations hub if you haven’t already
After that, explore in any order — take what is useful now, and return as your needs change
Each guide describes average responses and mechanisms — use your CGM data and care team to interpret what you observe

Education Self-discovery Type 1

Foundations (start here)

Foundations

Core principles of type 1 diabetes management — the knowledge everything else on this site builds on.

Open Foundations

Self-discovery and experimentation

Once Foundations are in place, progress comes from observing real glucose patterns, making small and safe changes, and adapting based on what actually happens. These guides support that process.

Observe — Learn — Adapt — Repeat

Fast and slow movers

How to understand and work with glucose movement between meals — the mechanisms behind rising and falling trends.

Explore fast and slow movers

Activity and movement

How movement amplifies insulin sensitivity — and the mechanisms behind glucose changes during and after different activity types.

Explore activity and movement

Dynamic Glucose Management

A framework for thriving with CGM — reading trends, understanding glucose context, and using data to guide self-discovery.

Explore Dynamic Glucose Management

Mealtime Insulin Guide

How the fat and protein content of meals affects glucose — and the mechanisms behind high-carb and high-fat meal responses.

Explore the Mealtime Insulin Guide

Exercise Guide

The physiology of exercise with type 1 diabetes — hypo risk, insulin on board, glucose responses, and how they interact.

Explore the Exercise Guide

Insulin On Board (IOB)

How the IOB setting works, why it matters for corrections, insulin stacking, and exercise hypo risk — and how it tends to behave across different systems.

Explore the IOB Guide

Insulin resistance

Why insulin resistance tends to be more pronounced in type 1 diabetes and how it interacts with glucose patterns, body composition, and energy.

Explore insulin resistance

Under 5s

Why early childhood type 1 diabetes presents unique physiological and practical challenges — and what the evidence describes about this distinct population.

Explore the Under 5s guide

Partying

The mechanisms behind alcohol and drug interactions with glucose and insulin in type 1 diabetes — what tends to happen and why.

Explore the Partying guide

Technology guides

CGM Guide

Choosing and using continuous glucose monitoring — accuracy, sensor selection, and getting the most from your device.

Explore the CGM Guide

Automated Insulin Delivery (AID) Guide

Choosing and using hybrid closed-loop systems — how AID algorithms work, and what to explore with your care team.

Explore the AID Guide

The IOB Trade-Off

How all four AID systems make different bets on insulin on board — and why understanding these design choices is essential for optimisation and exercise safety.

Read The IOB Trade-Off

Skincare for technology

Protecting skin while using CGM and pump devices — practical approaches to adhesion, reactions, and site care.

Explore the Skincare guide

Support this work

The Glucose Never Lies is built independently. If you would like to support the creation of resources like these, buy the GNL a coffee.

GNL guides and explorers are educational tools built from population-level evidence. They show average responses, not individual predictions — which is why your diabetes care team’s knowledge of you is always essential. Read the full GNL disclaimer.