[pimeys]

> They know french fries are bad, but think it's because they are deep fried. When I tell them that a regular baked potato or red potatoes have glycemic index values of around 85-89 and that potato ships are around 50-55 they are stunned.

Having T1D and a CGM I can say the normal potatoes are much easier to control compared to the french fries. The fat is really a huge problem if you dose your own insulin. It is guaranteed if I eat french fries that I don't need that much insulin right now, but the fatty food will raise my glucose levels in the next five hours. If I eat the fries for dinner, I can guarantee to be in the upper high levels at night when I sleep.

This is of course fixed with a closed loop system, but that doesn't help the T2Ds out there that much.

[turc1656]

Yes, fats slow the absorption rate of carbs so that makes sense that you will see a longer, protracted amount of time for the elevated blood sugar levels. You don't get the same spike and subsequent crash because it's more drawn out.

I also don't know if the fact that you are Type 1 instead of Type 2 affects anything I said. I don't know enough about Type 1 to comment. Anything I said is specific to Type 2.

[pimeys]

That's why I'm trying to comment with care. Just the facts how I can see fatty food with a CGM and a closed loop:

60g of carbs from french fries will mean you take insulin for about 40g of carbs now, then for 60g of carbs starting in one hour and divided to the next 2-3 hours.

For normal potatoes, 60g of carbs, you'd take insulin for the 60g right now and that's it.

You see how a combination of fat and carbs is really tricky when you need to keep a good control of your glucose values. There is good help for us T1 diabetics, algorithms such as oref1 with super micro boluses help to control the delay and additional raise of glucose when eating fatty food.

Ketosis is also something I'd never recommend to a T1D. It can lead to very nasty symptoms; cramps and headache. Can't say anything about T2Ds, people reading these should always consult a doctor before making any decisions of their treatment.