Overview
This page teaches you how to minimise the glucose spike after a high-carbohydrate meal with little fat.
These are meals and snacks where glucose rises fast because digestion is fast: the classic “carb hits first, insulin arrives late” problem.
If you need a refresher on the core model behind the whole site, start here: Episode 7: Fundamentals of The Glucose Never Lies.
Examples of high-carb, low-fat meals: breakfast cereals, jacket potato with baked beans, toast and jam, waffles with spaghetti hoops.
Examples of snacks: cereal bars, biscuits, rice crackers.
This page is not a free pass to live on ultra-processed food. The baseline remains: most meals should be well balanced. This page is about damage control when high-carb happens.
The detail
What happens after a high-carb, low-fat meal?
Here’s the basic pattern: carbohydrate enters the bloodstream quickly, but injected/pumped insulin rises slowly. So glucose gets a head start.
Why is there a spike?
Two core reasons.
1) The missing portal vein signal. In people without diabetes, insulin reaches the liver first via the portal vein. That early liver signal rapidly suppresses hepatic glucose output after eating. With injected insulin, that signal is weaker and delayed — so glucose rises more easily.
2) Slow insulin absorption. Whether you inject or pump, insulin still takes time to absorb and peak. High-carb meals often finish digesting before insulin has fully come online.
How do you knock the top off a spike?
You have two categories of tools:
Food-based options (to slow the rise):
- Choose whole-food carbohydrate options rather than heavily processed ones.
- Add vegetables to slow digestion.
- Add fat to keep the meal in the stomach longer.
- Add protein and eat the protein/veg first.
- Add vinegar to slow digestion.
Two options that are reliably effective (because they change the insulin–glucose timing mismatch):
- Give insulin a head start using S from SET.
- Use T from SET: do 10–15 minutes of moderate activity after eating (walking, playing, pottering, gardening).
This graphic shows how those tactics reduce the peak.
This guide pulls the strategy together:
Why this is not a lifestyle
This does not mean it’s fine to eat high-carb meals all the time. If high-carb, processed eating becomes the default, glucose becomes harder to manage and insulin demands rise — and you end up living in correction territory.
If you follow the typical Western pattern, this is what you can expect:
“Eat what you like, sit still, just keep whacking in the insulin.”
That approach reliably produces a worse life with type 1 diabetes: more highs, more corrections, more hypos, and more mental load.
Two mantras worth keeping close:
“I have low levels of insulin in my portal vein — I need to respect that.”
“You cannot outrun a high-carb processed diet with type 1 diabetes.”
What’s next
Next step: Balanced meals.
Mealtime insulin / related content
Navigate as you need.
