The FastDay Forum

[carorees]

This article gives a very interesting explanation of what drives us to crave carbohydrates:
http://diabeteshealth.com/read/2012/08/ ... ydrates--/

I was surfing the scientific literature to try to understand the role of leptin when I came across papers talking about the role of amylin working in synergy with leptin, which side-tracked me and I then came across this article. I need to investigate further as to the validity of these theories but they look plausible!

I wonder whether the improvements in insulin responsiveness we get with fasting also affect amylin which might result in our smaller appetites. Possibly the carb bingeing that affects some people starting on 5:2 is an early phase response where insulin and amylin are not yet adjusted.

Thoughts nerdy folk?

[carorees]

Well looky here: http://www.ncbi.nlm.nih.gov/pubmed/23438370

Protein in the diet can attenuate amylin responsiveness and fasting can increase it according to this study. Suggests that DrM's idea of fasting plus reducing protein can have more benefits than reducing IGF1 but might also be behind the improvement in appetite control with 5:2!

Did an amylase sneak in there by accident ?

Ketones can also suppress appetite.

[carorees]

Corrected typo!

So are carbs good or bad for the 5:2?

I thought high GI foods had to be avoided on fast days, not necessarily all carbs. I"m sur that was the main part of Mimi Spencer's chapter in the book if I remember correctly!

So are carbs good or bad for the 5:2?

People tend to avoid them on fast days although not completely.
Carbs are 'moreish'.
Protein and Fat are more satiating and you get feel fuller on less.

As to why we crave carbs- they are utilised preferentially before fat or protein.
There is a metabolic pathway called 'gluconeogenesis' whereby non-carb sources (such as protein and fat are converted to glucose in the body in order to be utilised.
This is what happens on a low carb fast day (and low carb days generally).

[carorees]

For most people, a high carb diet is probably not ideal when trying to lose weight. See my thread on weight loss and insulin resistance for info on why this may be important for some of us.