Overview
This page teaches you how to beat the missing portal vein insulin signal and get flat CGM lines after well-balanced meals.
Balanced meals are the workhorse of good control: they reduce volatility, lower the need for corrections, and make insulin timing predictable enough to learn from.
What “balanced” means here: half a plate of vegetables, with protein and carbohydrate making up the rest roughly equally.
Examples of meals: egg on toast with mushrooms; meat/fish/beans with potatoes and vegetables; jacket potato with cheese and salad.
Examples of snacks: whole fruit with nuts; full-fat yoghurt with nuts; nut butter on toast.
The detail
What happens after a balanced meal?
Balanced meals usually produce a smaller, slower rise than high-carb meals — but you can still see a spike if insulin timing is late.
Why is there still a spike?
Same two constraints as always.
1) Low insulin in the portal vein. In people without diabetes, insulin reaches the liver first via the portal vein and rapidly suppresses hepatic glucose output after eating. With injected/pumped insulin, that early liver signal is weaker and delayed — so glucose rises more easily.
2) Slow insulin absorption. Insulin still takes time to absorb and peak. If you dose too late, glucose gets the head start.
How do I get flat CGM lines after a balanced meal?
Two tactics reliably do the heavy lifting — both from SET:
- Give insulin a head start using S (state-based timing).
- Use T (ten minutes of light activity) after eating: walking, playing, pottering, gardening.
This graphic shows how those two tactics flatten the curve.
This guide puts everything in one place:
What results should you expect?
If you eat mostly balanced meals and apply these two tactics consistently, very high time in range becomes realistic for many people.
As a rough anchor: when balanced meals are the default and activity is feasible most of the time, many people can get to ~85%+ time in range without feeling like diabetes has eaten their life. Some will push higher; others will prioritise quality of life. Both can be rational.
Most people will still snack, travel, get ill, have unpredictable days, and occasionally miss the 10-minute activity. The goal is not “never deviate”. The goal is to make balanced meals the baseline so the rest is manageable.
What’s next
Next step: High-fat meals.
Mealtime insulin / related content
Navigate as you need.
- Mealtime insulin guide (hub)
- High-carbohydrate meals
- Balanced meals
- High-fat meals
- Mealtime insulin infographic
