Dr. Jason Fung promotes fasting longer and fewer meals to increase insulin sensitivity. My understanding is that the way to increase insulin sensitivity is to reduce your total insulin secretion. Why would one meal/day lead to less total insulin secretion than, lets say 2 meals/day if the total amount of food and is exactly the same? Are there papers demonstrating this? Have I missunderstood Dr. Jason Fung’s words?
I have been wondering this for years now, thanks in advance.
From what I understand is that ANYTIME you eat no matter what it is, your body has an insulin response. So Dr. Fung is saying that even if you eat low carb and low calories your body is still producing insulin. With low carb it’s just not as much. So when you fast and you have longer times in between eating then your insulin stays low.
Your understanding is wrong.
Insulin sensitivity is defined as your BG response to a given dosage of insulin. Even if you release the same amount of insulin whilst fasting you can potentially have a more favourable BG response with better sensitivity. It has nothing to do with the total amount of insulin secreted.
People with poor insulin sensitivity are not impeded by their insulin response, they’re impeded by the lack of BG response leading to elevated BG.
I’m a type 1 diabetic and I find this to be entirely true, in that I can dose less insulin after fasting because I am more sensitive to it.
I’m not a doctor, but I believe I understand this well enough to answer.
Insulin resistance is primarily induced by the constant presence of insulin. When you spend time in a fasted state, your cells become more sensitive to insulin as a result of its levels dropping so much.
The reason to want a longer fasting time is that it takes approximately 12 hours from the last meal to enter ketosis, at which point your metabolism is primarily running on fat (the liver converts some triglycerides into sugar, so your blood glucose and insulin levels never go to zero). The common 16-8 intermittent fasting window only gives you around 4 hours in ketosis with low insulin levels, whereas longer fasts give your body more time to adjust to low insulin.