From a certain perspective the human body is little more than a conduit or a tube, taking in and emitting in roughly equal measure.

It’s an elemental conception of human life that sees two reasonably balanced, opposite streams alternately feeding the organism essentials and sluicing away waste. It’s a perspective common to Chinese medicine and Hinduism (among other systems of esoteric thought), which makes it of heightened significance to the Indian city of Mumbai.

In Mumbai, the dividing line between the flow of ingress and egress is often so fine that the distinction is blurred. To a large extent, and for a large section of the population there is very little distinction at all.

People everywhere seem to be ingesting what has previously been passed and excreting almost to feed rather than to vent. The attitude to water supply and sewage in Mumbai has been so compromised by the demands of overpopulation and the environmental rigours of breakneck growth that its no wonder typhoid is rife in the slums. In a very real, and frightening sense, there’s a kind of Faustian toxic alchemy at work, switching the poles of ‘in’ and ‘out’, mixing the waters, crossing the streams.

A wet, vegetable smell, redolent of human vomit and loam wafts into the office. Workers immediately reach for the take-away menus. “Mmmm… Shall we order lunch, guys?” A sewage pipe is simply being de-blocked outisde the building. Reports abound of food poisoning from street food in the days when the sewers are exposed.

The bathroom I use in the home I recently rented a room in in Mumbai is separated from the kitchen of the family of four by a chipboard partition that doesn’t quite reach the outer wall. When I am sitting on the toilet and the lady of the house is frying, there’s the continual possibility of a fine mist of burning fat droplets fountaining over the wall to enliven early morning ablutions.

With a bit of effort, we could shake hands during our respective processes like the first excited penetrators of the Berlin wall. I wonder how the aromas emanating from my bathroom don’t enter the flavour of the delicious food she makes. If I leave a cut raw onion in a fridge with a pot of opened yoghurt, I can’t really complain if the stuff turns out tasting more like raitha than Müller Lite, now can I?

Years ago, a very dear friend of mine came up with an ingenious method of balancing the flows. He called it the ‘Shit/Weight Plan’.

According to this system, weight can be easily controlled, gained or lost through the judicious application of weighing scales at the two ends of the process. His theory was that if one only consumed an equal poundage to that amount dropped off, a steady weight would be maintained. If one troughed more than one sloughed, weight would be put on; if one dumped more than one scrumped then weight would be shed.

The domestic setup that my landlady and I have is ripe for a field test of the Shit/Weight Plan. If she pushes them far enough to her right, Sibyl and I could cut out the middle man and share the kitchen scales, one pan each; shouting the differentials to each other through the partition as we go.