Drinking water before food is less benficial.
You can end up expanding the Stomach lining, and feel fuller before you eat, this then makes some people want to eat less, when they start feeling bloated, thus getting inadequate nutrition.
I've not hear of the reduced absoprtion theory drinking water after eating.
Here's one way opf looking at it.
Water has no calories, so if you had some after meals, you would probably absorb most of the water into the undigested food.
The water has less molecules in it, being liquid, than food will, so despite the Stomach contents gaining more volume, as a result of adding in water afterwards, you could say the overall molecular structure is less rigid, and more flexible, helping to give better breakdown.
Especially give nas I sai dater has 0 calories, so that wouldn't result in increased absoprion time, in the intestines.
The only way I can see if water was to affect absorption, is if the increased food volume in the gut, when water was added, seperated the nutrients a little bit further from each other, possibly meaning the food was absorbing over a larger area of the gut, and utilising more Villi, thereby not allowing the Villi to function at maximal capability.
The other thing to bear in mind is, most food doesn't process in the Stomach anyway.
The Stomach acts as a holding zone, and at regular intervals it releases bits of undigested food matter into the Duodenum, and then into the Illium, where the little Villi assist in the processing of the nutrient content.
So even if you drank water 1 hour after a meal, instead of straight after, bearing in mind most food nutrition is processed in a 3 hour time span, you'd effectively be slowing down the absorption of 2/3 or 66.66% of your food, if the theory is true, abou water slowing food absorption down.
You would then have to make sure that absorption thing wasn't happening by drinking water 3 hours after meal, which]
A: won't work if someone eats every 2-2.5 hours
B: even on a 3 hour meal space, you'd be filling up with water before your next meal, and then eat food, getting that partial bloat sensation / effect, I described earlier.