I was reading through the comments on Stephan Guyenet’s blog where he wrote his impressions following McDougall’s Advanced Study Weekend. He presented there. Guyenet made this comment:

“Type 1 diabetes is not going to be improved by a high-carb diet, at least it’s extremely difficult to imagine mechanistically.”

As you know, type 1 diabetes can be improved by a high-carb, low-fat diet. Dietary fat has been shown to increase glucose levels and insulin requirements in people with type 1:

Dietary Fat Acutely Increases Glucose Concentrations And Insulin Requirements In Patients With Type 1 Diabetes, Diabetes Care, April 2013.

I’ve written quite a bit about mechanisms for how dietary fat impacts glucose uptake. It seems to be related to a reduction in insulin sensitivity, which people with type 1 diabetes can experience:

1. Fat can affect body weight and body composition, which can affect insulin sensitivity.
2. Fat can make cell membranes more or less fluid, affecting insulin sensitivity.
3. Fatty acids can control how genes get expressed, affecting insulin sensitivity.

As I’ve said before, there must be something else working too, something more immediate, because when you give people with type 1 diabetes a high-fat meal and a low-fat meal, they need more insulin to cover the high-fat meal, even though both meals contain the same amount of carbohydrate and protein: