A sincere smile invokes the entire face. It starts at the mouth, where the edges of the lips curl up and the cheeks rise, and ends with the eyes, which crease and shine. A genuine grin comes more from the eyes than anywhere else. They beam. A true Bengali smile follows this pattern only to an extreme. The edge of the lips look as if they are trying to leap off the face, the cheeks form little hills, and the eyes shine in their now deeply crinkled recesses. It’s easy to get one of these smiles in Dhaka; I manage it every time I speak Bengali.

We are about 2 weeks into Ramadan, the holy month where Muslims fast throughout the day to purify themselves and train their minds and bodies to be good and just in the coming year. As atheists and Christians we are not expected to participate in the fasting, but living in a predominately Muslim country there are still implications on our diet. As a matter of courtesy we do not eat or drink in front of our hosts during the day.

The cafeteria where we eat most of our meals is still open, but offers a limited selection of food (even more limited than rice and curry). Now breakfast and lunch is bought in the local supermarket, Agora, and taken in our room. We’re eating a lot of fruit and drinking a lot of water, supplemented with bread and biscuits. This partially self-imposed diet has been nicknamed the Singapore Slim for reasons that I’m not entirely sure of.

The Singapore slim is a powerful weight loss diet, since in effect it involves only eating one meal a day. I’m planning to market it along similar lines to the Atkins diet. I think there’s some money to be made here. To achieve your weight loss dreams all you need to do is move to an Islamic country during Ramadan and live according to the customs of your surroundings. It is simple to use: there’s no point counting, no calculations – just dramatic weight loss that would make a supermodel convulse with envy.