I posted a while back about my son's type 1 diabetes diagnoses about 20 months ago. I personally have always favored a diet with 100-150 grams of carbs a day diet to lose fat and eating high fat. It certainly worked, but my son has now gone through periods with injected insulin where he ate 60%+ carbs with less than 30% fat and periods where he ate 20% carbs with high fat.
The shocking surprise was that he needed just as much insulin with 100 grams of carbs a day as with 300 grams of carbs a day, and much more insulin per gram of carbs on the high fat diet. So long as his calories were fairly constant, the reduction in carbs on a high fat diet is cancelled out by an increase in insulin required per gram of carbs. In other words he developed a kind of relative insulin resistance on a high fat diet that forced him to need much more insulin for the same amount of carbs, and the SAME amount of insulin overall to manage his diabetes through injected insulin.
SO a high fat, low carb diet does not seem to reduce the amount of insulin that he needs to inject, and by extension would not seem to reduce the amount of insulin secreted by a non-diabetic individual. This was a surprise to me. As a result I have been researching this phenomenon and found that muscle cells stop making glucose burning enzymes, and stop storing as much glycogen, while conversely making more fat burning enzymes and storing more fatty acids on a higher fat diet and that this makes the muscles poorer glucose burners and in effect it makes them relatively insulin resistant. There may be similar effect on the liver.
Studies have also found that individuals on higher fat diets will have higher fasting blood sugars and will also often fail glucose tolerance tests. It seems to be a short term phenomenon, but my basic question is, why do people turn to a low carb, high fat diet if it does not reduce the need for the body to produce insulin?
It DOES tend to lower peak blood sugars, and it does tend to prevent between meal hunger, but low carb, high fat does NOT seem to reduce the amount of insulin that the body need produce and secrete on a daily basis.
My son currently eats a variety of food and tends to get moderate carbs and higher fat, and the result is fairly stable blood sugar with relatively few low or very high blood sugars like a lot of kids, but it does not reduce his overall daily insulin needs at all.
For example, he typically eats about 30-40 grams of carbs at a meal with about 50% fat and about 500-600 calories. This would require about 3-4 units of insulin, but if he eats the same amount of calories with 100 grams of carbs, therefore 75-80% carbs (which we tested for 2-3 weeks) he still only needs 3-4 units of insulin for the 100 grams of carbs!
Anyway this has changed my view somewhat on how I feel about low carb diets as they clearly seem to make insulin less effective per gram of carbs almost in direct proportion to the reduction in carbs, ie no change in insulin needs.