how do you like your veggies… cooked or raw?

So what effect does cooking have on veggies?  Is raw better than cooked when it comes to fibre and insulin demand?

To help us understand the effect of cooking the table below shows a comparison of the fibre in a selection of one hundred grams of cooked and raw vegetables.





fibre % insulin carbs fibre

% insulin

spinach 4 2 40% 4 2 40%
broccoli 7 3 54% 7 3 49%
eggplant 6 3 40% 8 3 63%
artichoke 11 5 49% 12 9 29%
mushroom 5 1 55% 5 2 44%
carrots 10 3 66% 8 3 60%

Spinach and broccoli when cooked don’t seem to lose a lot of their fibre.

You could eat 600g of spinach or 300g of broccoli and still have a Bernstein-compliant lunch of dinner (i.e. no more than 12g of carbs).

Eggplant seems to lose some fibre relative to carbohydrates and ends up with an increased percentage of insulinogenic calories.

If you boil something to a mush then it’s probably not going to have the same quality of fibre as if you were to eat it in its raw unprocessed form.  It’s also going to be easier to eat a lot more cooked veggies than lightly steamed or raw veggies.

Lightly steamed is probably your best bet to retain the nutrients and fibre in your veggies.  If you want to check out how your favourite veggies fare before and after cooking you can find out at

In view of the growing body of research showing that fibre is good for gut health which is in turn good for diabetes, insulin sensitivity and a whole host of other issues I think it’s hard to build a strong case for avoiding vegetables altogether just to minimise carbohydrates.

[next article…  putting it all together… protein and net carbs] [this post is part of the insulin index series] [Like what you’re reading?  Skip to the full story here.]

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Marty Kendall

  • olsbeanKeith says:

    Thank you for hard work but I’m confused Marty, for example “Spinach 35% Insulin”, but in your article THE MOST KETOGENIC DIET FOODS, Spinach is listed as 15% insulinogenic, same with the other veg, what am I not understanding?

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