Boiled potatoes & Area Under the Curve (AUC): some thoughts.

Here are three "curves"... a 4 x 1 rectangle, a 2 x 2 square and a 1 x 4 rectangle.

The AUC for all three "curves" = 4.

Imagine that the three curves are for blood glucose level increase above baseline vs time.

a) "X" grams of a high-Glycaemic Index (GI) carb e.g. glucose, maltodextrin or amylopectin will result in a large glucose response that goes away rapidly, as the carbs pass into the blood rapidly and are cleared from the blood rapidly due to the large insulin response.

b) "X" grams of a 50:50 mixture of high & low-GI carbs will result in a lower but longer sustained glucose & insulin response, as the carbs (are converted into glucose slowly and) pass into the blood slowly and are cleared from the blood slowly due to the small insulin response.

c) "X" grams of a low-GI carb e.g. amylose or resistant starch will result in an even lower glucose & insulin response that is sustained for even longer, as the carbs (are converted into glucose very slowly and) pass into the blood very slowly and are cleared from the blood very slowly due to the very small insulin response.

Will a), b) & c) produce the same satiety? I think not. I think that a) will produce lower satiety than b) or c). Whether hunger is caused by a sudden drop in blood glucose level or by a sudden drop in the amount of nutrients in the gut, I don't know.

The reason for this post is A satiety index of common foods (full study) and the related study An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods.

In the first study, boiled potatoes produced the highest satiety, yet in the second study, boiled potatoes produced one of the highest glucose & insulin AUCs. How can this be? Consider the preparation method for the Russet potatoes:-
"Peeled, boiled for 20 min, and stored at 4 °C overnight; reheated in a microwave oven for 2 min immediately before serving."

Potato starch when refrigerated, produces resistant starch, which has a low GI (see item 605 in International table of glycemic index and glycemic load values: 2002). Therefore, refrigerated potatoes contain a mixture of high & low-GI starches. This, I believe, is why boiled, refrigerated & reheated potatoes produced the highest satiety. The combination of water, fibre & resistant starch kept hunger pangs away the longest. I suspect that boiled potatoes that are eaten hot won't produce as much satiety, as they contain no resistant starch.

Has anyone compared the satiety of freshly-boiled potatoes with boiled & refrigerated potatoes?

It's all about ME, baby! (Birth - 1997)

It's all about ME, baby! (1997 - present) is my story after discovering the Atkins Diet. This is my story up to that point. I was born one snowy Winter's day. Mum told me that my cot was placed next to an open window in Central Middlesex Hospital. That explains a lot! Here's mum, me and my sister.


I don't remember much about my early years. As we were relatively poor (dad was a tailor and mum did typing for a solicitor), getting regular French Fancies & Corona lemonade deliveries was considered a status symbol. I ran around in the street with other kids of my age but I was fat. I was also very short for my age (insufficient GH from my pituitary?) and was rubbish at sports in primary school. Here's a photo taken when I was about 9 or 10. I'm the shortest boy in the picture.


Stripy shirts were all the rage, apparently. Even at this tender age, I used to regularly fall asleep after eating a plate of chips.

In secondary school, sports was dreadful what with having to play cricket using a cricket ball (instead of a tennis ball), contact sports, swimming and showers. Being short, fat & under-developed, I was embarrassed to get undressed in front of my peers, so I developed the art of forging sick notes in my mum's handwriting. I was a very sickly child! ;-D

My forging skills resulted in the total avoidance of swimming (also contact sports, cross-country running etc) and a big improvement in the quality of my handwriting! With tennis, I had to travel to a tennis court by train. I didn't mind doing that, as there were no showers at the tennis courts and I could play the game for a while until I overheated. Secondary school was where I developed a total hatred for almost all sports and when I left, that was the end of exercise as far as I was concerned. When I left secondary school at the age of 18, I was 4 feet 9 inches tall.

At university, I would have a cheese & ham salad baguette washed down with a can of Coke (non-diet in those days) for lunch, followed by a snooze.

At work, I would have a cheese & raw onion roll washed down with a can of Coke for tea-break, followed by a snooze. Here's me at the age of 26. At some point, my pituitary gland "woke up" and secreted GH, as I grew to 6 feet 1 inch tall in my late twenties.


I did manage to get some work done!

When I was dating, I jogged/walked for over 4 miles a day to see my girlfriend. I got slim. After I married, that stopped and as I was a skint Electronic Engineer and Lesley was a skint Cake Decorator, my diet was predominantly cheap carbohydrates, like bread, pasta, potatoes & rice. The result? Lots of snoozes + lots of weight gain. I was a lazy git, apparently.

In 1992, Lesley left to live with her mother. In 1994, I started dating Eileen. At parties, I became (in)famous for falling asleep after eating nibbles made from refined carbohydrates.