Categories: Comments and Science.

The Dominion Post 28/10/14 had an article about the effects of reheating pasta on its Glycaemic Index (GI).

It is well known that when pasta is cooled it gives a lower spike of blood sugar (i.e. lower GI). It was assumed that when it is reheated that the pasta would revert to producing high blood sugar.

This reheating theory was tested by 5:2diet author Dr Micheal Mosley and Trust Me, I’m a Doctor, Chris van Tulleken from University College London. The results of this research is groundbreaking – not only did the reheated pasta not revert to its origin higher GI, its GI actually dropped even further to 50% of its original blood sugar spike.

This information is critical for people who want to look after their weight and health and also want to enjoy pasta now and then. Our advice to these people is to prepare the pasta, put in the fridge then reheat and voila same delicious hot pasta meal with potentially half the fattening insulin spiking blood sugar. Apparently the reheated pasta behaves more like fibre and less sugar is absorbed as it moves along the gastrointestinal tract to feed good bacteria in the lower gut. The lower insulin spike also results in a lower insulin response which equals better health outcomes as well as less body fat storage.

Based on this research our advice is that inclusion of small amounts of reheated pasta is possible in a healthy diet provided it is taken into consideration that pasta is still a relatively high sugar product and it contains little in important vitamins and minerals compared to non-starchy vegetables. So we suggest small amounts of reheated pasta with lots of favourable vegetables and balancing lean protein and healthy fat now and then.

The question remains, what about the effect of cooling and reheating bread, potatoes and other starchy foods? Dr Mosely was questioned about this on Radio NZ’s Sunday Morning programme 2/11/14 and he said the research needed to be done but he had every reason to believe that the starch in these foods would behave in the same way making them much more favourable. Dr Mosely then gave his own example of keeping his wholegrain bread in the freezer then toasting it to reheat it.  One wonders about the effect on GI of multiple heating and cooling of starchy foods.

Contributed by Kevin Bateman