I’m a keto T1D, diabetic since 1986, keto since 2015, and on an insulin pump since 2015 too.
There’s no magic formula - like reduce basal insulin by x and bolus insulin by y, because obviously everyone’s different, but I have made dramatic changes to my diet and diabetes management since starting eating keto.
I test, test, test ALL the time - mostly using a Freestyle Libre flash monitor, but also fingerpricks. That’s my non-negotiable - if I’m not testing, I wouldn’t have a clue. I need that data to work with!
I am on less insulin than I was before I went keto, but it’s been a gradual process as a result of lots of trial and error. It’s worth it, though.
If I’m taking small amounts of insulin (thanks to being keto) than the outcomes of any errors are by their very nature smaller. That makes me feel much safer than when I’d been used to taking a tonne of insulin when I’d go out for pizza, garlic bread and ice cream, go massively high afterwards and then hypo a couple of hours after that! An absolute rollercoaster!
I eat two scrambled eggs with butter for breakfast, and despite their negligible carbohydrate value, I nevertheless need 1.4u of rapid-acting insulin to keep my blood sugar from spiking.
Lunch is low-carb soup, or a chaffle (waffle made with cheese and egg) filled with ham or cheese or egg or creamy mushrooms or homemade pate or tuna mayo or whatever - I generally take one to two units with a lunch like these - and for my evening meal, my carb count varies quite a lot (homemade bolognese racks up quite a count thanks to the tomatoes and peppers, and fatty puddings tend to spike a bit too) and I’ll have anything between 2.5u (salmon and broccoli), 3.5u (when I’m having something like steak, cream cheese sauce and broccoli) and 4.5u (cauli bolognese), depending on what I’m having.
Protein and fat in the absence of carbs do still create a demand for insulin in my case. But the only way to find out to what extent is to keep testing.
As soon as I found I was no longer chasing excess carbs with insulin, and excess insulin with carbs, I discovered a much better relationship with food and I’m having far fewer hypos. And I’m very happy with my HbA1c of 37mmol/mol.
I found out about LCHF and subsequently this forum thanks to @MarkGossage when I was an active member of diabetes.co.uk/forum - take a look and see how other LCHF and keto T1s tackle it.
My diabetes specialist nurse knows that I avoid carbs, and she is very polite about it without going into it. The comment I tend to get is ‘we wouldn’t recommend it’.
But it’s my life, my health and my T1. And I’m absolutely thriving.