It has long been understood how starchy foods such as pasta, rice, and potato become what are known as ‘resistant starches’ once allowed to cool and are reheated. Some recent info from Sri Lankan researchers suggests that eating cooled starches can actually slow the glycaemic response (blood sugar rise). They suggest that this is because the cooling process causes hydrogen bonds to form between the amylose molecules, in turn converting the rice (for example) into resistant starch.
The British Nutrition Foundation agree that resistant starch may be beneficial to overall health, including improved digestion as well as regulating blood sugar levels.
BBC News, (2015). 'Eat rice cold for fewer calories'. Retrieved 24th March, 2015, from http://www.bbc.co.uk/news/health-32019176