By adding a fat such as coconut oil before cooking, and then immediately cooling the rice, the starch composition of the rice alters so that it becomes more resistant to digestion.
The oil works by interacting with the starch molecules and changing its architecture. "Cooling for 12 hours will lead to formation of hydrogen bonds between the amylose molecules outside the rice grains which also turns it into a resistant starch," explained James in a press release. And he notes that heating the rice back up afterwards doesn’t change the resistant starch levels.
Mind you, if you’re living on a bowl of rice a day, you probably WON’T want to reduce your calorie intake.